Changed default from ES3 to ES5

Fixes microsoft#10117

The fix was easy, but then I had to get the tests passing:

```shell
$ gulp runtests # loads of failures, more than 1000 actually.
$ gulp baseline-accept
$ gulp runtests # to make sure they now passed
```

...and then `git add .` to add all the changes. (There were a bunch of new files created when I did it like this; is that correct?)

----

(Regarding the unrelated changes in `compileOnSave.ts`: I happened to see a few typing mistakes there very close to the changes I were making to that files, so I bundled that change along at the same time. Since the tests are passing I think it should be fine.)

Author: perlun

src/compiler/core.ts

@@ -1486,7 +1486,7 @@ namespace ts {
     }
 
     export function getEmitScriptTarget(compilerOptions: CompilerOptions) {
-        return compilerOptions.target || ScriptTarget.ES3;
+        return compilerOptions.target || ScriptTarget.ES5;
     }
 
     export function getEmitModuleKind(compilerOptions: CompilerOptions) {

src/harness/unittests/compileOnSave.ts

@@ -558,13 +558,13 @@ namespace ts.projectSystem {
 
             const expectedEmittedFileName = "/a/b/f1.js";
             assert.isTrue(host.fileExists(expectedEmittedFileName));
-            assert.equal(host.readFile(expectedEmittedFileName), `"use strict";\r\nexports.__esModule = true;\r\nfunction Foo() { return 10; }\r\nexports.Foo = Foo;\r\n`);
+            assert.equal(host.readFile(expectedEmittedFileName), `"use strict";\r\nObject.defineProperty(exports, "__esModule", { value: true });\r\nfunction Foo() { return 10; }\r\nexports.Foo = Foo;\r\n`);
         });
 
-        it("shoud not emit js files in external projects", () => {
+        it("should not emit js files in external projects", () => {
             const file1 = {
                 path: "/a/b/file1.ts",
-                content: "consonle.log('file1');"
+                content: "console.log('file1');"
             };
             // file2 has errors. The emitting should not be blocked.
             const file2 = {
@@ -601,4 +601,4 @@ namespace ts.projectSystem {
             assert.isTrue(outFileContent.indexOf(file3.content) === -1);
         });
     });
-}
+}

tests/baselines/reference/APISample_compile.js

@@ -45,7 +45,7 @@ compile(process.argv.slice(2), {
          at: https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#a-minimal-compiler
  *       Please log a "breaking change" issue for any API breaking change affecting this issue
  */
-exports.__esModule = true;
+Object.defineProperty(exports, "__esModule", { value: true });
 var ts = require("typescript");
 function compile(fileNames, options) {
     var program = ts.createProgram(fileNames, options);

tests/baselines/reference/APISample_linter.js

@@ -70,7 +70,7 @@ fileNames.forEach(fileName => {
          at: https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#traversing-the-ast-with-a-little-linter
  *       Please log a "breaking change" issue for any API breaking change affecting this issue
  */
-exports.__esModule = true;
+Object.defineProperty(exports, "__esModule", { value: true });
 var ts = require("typescript");
 function delint(sourceFile) {
     delintNode(sourceFile);

tests/baselines/reference/APISample_parseConfig.js

@@ -42,7 +42,7 @@ export function createProgram(rootFiles: string[], compilerOptionsJson: string):
          at: https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#a-minimal-compiler
  *       Please log a "breaking change" issue for any API breaking change affecting this issue
  */
-exports.__esModule = true;
+Object.defineProperty(exports, "__esModule", { value: true });
 var ts = require("typescript");
 function printError(error) {
     if (!error) {

tests/baselines/reference/APISample_transform.js

@@ -22,7 +22,7 @@ console.log(JSON.stringify(result));
          at: https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#a-simple-transform-function
  *       Please log a "breaking change" issue for any API breaking change affecting this issue
  */
-exports.__esModule = true;
+Object.defineProperty(exports, "__esModule", { value: true });
 var ts = require("typescript");
 var source = "let x: string  = 'string'";
 var result = ts.transpile(source, { module: ts.ModuleKind.CommonJS });

tests/baselines/reference/APISample_watcher.js

@@ -116,7 +116,7 @@ watch(currentDirectoryFiles, { module: ts.ModuleKind.CommonJS });
          at: https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#incremental-build-support-using-the-language-services
  *       Please log a "breaking change" issue for any API breaking change affecting this issue
  */
-exports.__esModule = true;
+Object.defineProperty(exports, "__esModule", { value: true });
 var ts = require("typescript");
 function watch(rootFileNames, options) {
     var files = {};

tests/baselines/reference/ES3For-ofTypeCheck1.errors.txt

@@ -0,0 +1,4 @@
+=== tests/cases/conformance/statements/for-ofStatements/ES3For-ofTypeCheck1.ts ===
+for (var v of "") { }
+>v : Symbol(v, Decl(ES3For-ofTypeCheck1.ts, 0, 8))
+

tests/baselines/reference/ES3For-ofTypeCheck1.symbols

@@ -0,0 +1,5 @@
+=== tests/cases/conformance/statements/for-ofStatements/ES3For-ofTypeCheck1.ts ===
+for (var v of "") { }
+>v : string
+>"" : ""
+

tests/baselines/reference/ES3For-ofTypeCheck1.types

@@ -0,0 +1,8 @@
+=== tests/cases/conformance/statements/for-ofStatements/ES3For-ofTypeCheck4.ts ===
+var union: string | string[];
+>union : Symbol(union, Decl(ES3For-ofTypeCheck4.ts, 0, 3))
+
+for (const v of union) { }
+>v : Symbol(v, Decl(ES3For-ofTypeCheck4.ts, 1, 10))
+>union : Symbol(union, Decl(ES3For-ofTypeCheck4.ts, 0, 3))
+

tests/baselines/reference/ES3For-ofTypeCheck4.errors.txt

@@ -0,0 +1,8 @@
+=== tests/cases/conformance/statements/for-ofStatements/ES3For-ofTypeCheck4.ts ===
+var union: string | string[];
+>union : string | string[]
+
+for (const v of union) { }
+>v : string
+>union : string | string[]
+

tests/baselines/reference/ES3For-ofTypeCheck4.symbols

@@ -120,7 +120,7 @@ sourceFile:ES5For-of33.ts
 >>>catch (e_1_1) { e_1 = { error: e_1_1 }; }
 >>>finally {
 >>>    try {
->>>        if (_b && !_b.done && (_c = _a["return"])) _c.call(_a);
+>>>        if (_b && !_b.done && (_c = _a.return)) _c.call(_a);
 >>>    }
 >>>    finally { if (e_1) throw e_1.error; }
 >>>}

tests/baselines/reference/ES3For-ofTypeCheck4.types

@@ -176,7 +176,7 @@ sourceFile:ES5For-of34.ts
 >>>catch (e_1_1) { e_1 = { error: e_1_1 }; }
 >>>finally {
 >>>    try {
->>>        if (_b && !_b.done && (_c = _a["return"])) _c.call(_a);
+>>>        if (_b && !_b.done && (_c = _a.return)) _c.call(_a);
 >>>    }
 >>>    finally { if (e_1) throw e_1.error; }
 >>>}

tests/baselines/reference/ES5For-of33.js

@@ -134,7 +134,7 @@ sourceFile:ES5For-of35.ts
 >>>catch (e_1_1) { e_1 = { error: e_1_1 }; }
 >>>finally {
 >>>    try {
->>>        if (_b && !_b.done && (_f = _a["return"])) _f.call(_a);
+>>>        if (_b && !_b.done && (_f = _a.return)) _f.call(_a);
 >>>    }
 >>>    finally { if (e_1) throw e_1.error; }
 >>>}

tests/baselines/reference/ES5For-of33.sourcemap.txt

@@ -150,7 +150,7 @@ sourceFile:ES5For-of36.ts
 >>>catch (e_1_1) { e_1 = { error: e_1_1 }; }
 >>>finally {
 >>>    try {
->>>        if (_b && !_b.done && (_f = _a["return"])) _f.call(_a);
+>>>        if (_b && !_b.done && (_f = _a.return)) _f.call(_a);
 >>>    }
 >>>    finally { if (e_1) throw e_1.error; }
 >>>}

tests/baselines/reference/ES5For-of34.js

@@ -1,12 +1,9 @@
-tests/cases/compiler/MemberAccessorDeclaration15.ts(2,8): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
 tests/cases/compiler/MemberAccessorDeclaration15.ts(2,12): error TS2369: A parameter property is only allowed in a constructor implementation.
 
 
-==== tests/cases/compiler/MemberAccessorDeclaration15.ts (2 errors) ====
+==== tests/cases/compiler/MemberAccessorDeclaration15.ts (1 errors) ====
     class C {
        set Foo(public a: number) { }
-           ~~~
-!!! error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
                ~~~~~~~~~~~~~~~~
 !!! error TS2369: A parameter property is only allowed in a constructor implementation.
     }

tests/baselines/reference/ES5For-of34.sourcemap.txt

@@ -31,7 +31,7 @@ export module A {
 
 //// [part1.js]
 "use strict";
-exports.__esModule = true;
+Object.defineProperty(exports, "__esModule", { value: true });
 var A;
 (function (A) {
     var Utils;
@@ -45,7 +45,7 @@ var A;
 })(A = exports.A || (exports.A = {}));
 //// [part2.js]
 "use strict";
-exports.__esModule = true;
+Object.defineProperty(exports, "__esModule", { value: true });
 var A;
 (function (A) {
     // collision with 'Origin' var in other part of merged module

tests/baselines/reference/ES5For-of35.js

@@ -0,0 +1,36 @@
+=== tests/cases/conformance/classes/propertyMemberDeclarations/memberAccessorDeclarations/accessorWithES3.ts ===
+// error to use accessors in ES3 mode
+
+class C {
+>C : Symbol(C, Decl(accessorWithES3.ts, 0, 0))
+
+    get x() {
+>x : Symbol(C.x, Decl(accessorWithES3.ts, 2, 9))
+
+        return 1;
+    }
+}
+
+class D {
+>D : Symbol(D, Decl(accessorWithES3.ts, 6, 1))
+
+    set x(v) {
+>x : Symbol(D.x, Decl(accessorWithES3.ts, 8, 9))
+>v : Symbol(v, Decl(accessorWithES3.ts, 9, 10))
+    }
+}
+
+var x = {
+>x : Symbol(x, Decl(accessorWithES3.ts, 13, 3))
+
+    get a() { return 1 }
+>a : Symbol(a, Decl(accessorWithES3.ts, 13, 9))
+}
+
+var y = {
+>y : Symbol(y, Decl(accessorWithES3.ts, 17, 3))
+
+    set b(v) { }
+>b : Symbol(b, Decl(accessorWithES3.ts, 17, 9))
+>v : Symbol(v, Decl(accessorWithES3.ts, 18, 10))
+}

tests/baselines/reference/ES5For-of35.sourcemap.txt

@@ -0,0 +1,40 @@
+=== tests/cases/conformance/classes/propertyMemberDeclarations/memberAccessorDeclarations/accessorWithES3.ts ===
+// error to use accessors in ES3 mode
+
+class C {
+>C : C
+
+    get x() {
+>x : number
+
+        return 1;
+>1 : 1
+    }
+}
+
+class D {
+>D : D
+
+    set x(v) {
+>x : any
+>v : any
+    }
+}
+
+var x = {
+>x : { readonly a: number; }
+>{    get a() { return 1 }} : { readonly a: number; }
+
+    get a() { return 1 }
+>a : number
+>1 : 1
+}
+
+var y = {
+>y : { b: any; }
+>{    set b(v) { }} : { b: any; }
+
+    set b(v) { }
+>b : any
+>v : any
+}