Fix binder inStrictMode initialization (#625)

Author: frodi-karlsson

internal/binder/binder.go

@@ -117,6 +117,7 @@ func bindSourceFile(file *ast.SourceFile, options *core.CompilerOptions) {
 		b.file = file
 		b.options = options
 		b.languageVersion = options.GetEmitScriptTarget()
+		b.inStrictMode = options.AlwaysStrict.IsTrue()
 		b.unreachableFlow = b.newFlowNode(ast.FlowFlagsUnreachable)
 		b.reportedUnreachableFlow = b.newFlowNode(ast.FlowFlagsUnreachable)
 		b.bind(file.AsNode())

testdata/baselines/reference/submodule/compiler/alwaysStrict.errors.txt

@@ -0,0 +1,9 @@
+alwaysStrict.ts(2,9): error TS1100: Invalid use of 'arguments' in strict mode.
+
+
+==== alwaysStrict.ts (1 errors) ====
+    function f() {
+        var arguments = [];
+            ~~~~~~~~~
+!!! error TS1100: Invalid use of 'arguments' in strict mode.
+    }

testdata/baselines/reference/submodule/compiler/alwaysStrict.errors.txt.diff

@@ -0,0 +1,9 @@
+alwaysStrictES6.ts(2,9): error TS1100: Invalid use of 'arguments' in strict mode.
+
+
+==== alwaysStrictES6.ts (1 errors) ====
+    function f() {
+        var arguments = [];
+            ~~~~~~~~~
+!!! error TS1100: Invalid use of 'arguments' in strict mode.
+    }

testdata/baselines/reference/submodule/compiler/alwaysStrictES6.errors.txt

@@ -0,0 +1,11 @@
+alwaysStrictModule.ts(3,13): error TS1100: Invalid use of 'arguments' in strict mode.
+
+
+==== alwaysStrictModule.ts (1 errors) ====
+    module M {
+        export function f() {
+            var arguments = [];
+                ~~~~~~~~~
+!!! error TS1100: Invalid use of 'arguments' in strict mode.
+        }
+    }

testdata/baselines/reference/submodule/compiler/alwaysStrictES6.errors.txt.diff

@@ -0,0 +1,21 @@
+a.ts(3,13): error TS1100: Invalid use of 'arguments' in strict mode.
+b.ts(3,13): error TS1100: Invalid use of 'arguments' in strict mode.
+
+
+==== a.ts (1 errors) ====
+    module M {
+        export function f() {
+            var arguments = [];
+                ~~~~~~~~~
+!!! error TS1100: Invalid use of 'arguments' in strict mode.
+        }
+    }
+    
+==== b.ts (1 errors) ====
+    module M {
+        export function f2() {
+            var arguments = [];
+                ~~~~~~~~~
+!!! error TS1100: Invalid use of 'arguments' in strict mode.
+        }
+    }

testdata/baselines/reference/submodule/compiler/alwaysStrictModule.errors.txt

@@ -0,0 +1,11 @@
+alwaysStrictNoImplicitUseStrict.ts(3,13): error TS1100: Invalid use of 'arguments' in strict mode.
+
+
+==== alwaysStrictNoImplicitUseStrict.ts (1 errors) ====
+    module M {
+        export function f() {
+            var arguments = [];
+                ~~~~~~~~~
+!!! error TS1100: Invalid use of 'arguments' in strict mode.
+        }
+    }

testdata/baselines/reference/submodule/compiler/alwaysStrictModule.errors.txt.diff

@@ -1,18 +1,11 @@
 --- old.alwaysStrictNoImplicitUseStrict.errors.txt
 +++ new.alwaysStrictNoImplicitUseStrict.errors.txt
-@@= skipped -0, +-1 lines =@@
+@@= skipped -0, +0 lines =@@
 -error TS5102: Option 'noImplicitUseStrict' has been removed. Please remove it from your configuration.
--alwaysStrictNoImplicitUseStrict.ts(3,13): error TS1100: Invalid use of 'arguments' in strict mode.
--
--
+ alwaysStrictNoImplicitUseStrict.ts(3,13): error TS1100: Invalid use of 'arguments' in strict mode.
+ 
+ 
 -!!! error TS5102: Option 'noImplicitUseStrict' has been removed. Please remove it from your configuration.
--==== alwaysStrictNoImplicitUseStrict.ts (1 errors) ====
--    module M {
--        export function f() {
--            var arguments = [];
--                ~~~~~~~~~
--!!! error TS1100: Invalid use of 'arguments' in strict mode.
--        }
--    }
-@@= skipped --1, +1 lines =@@
-+<no content>
+ ==== alwaysStrictNoImplicitUseStrict.ts (1 errors) ====
+     module M {
+         export function f() {