Expose TypeChecker. getAwaitedType to public

Author: yeonjuan

src/compiler/types.ts

@@ -4968,7 +4968,6 @@ export interface TypeChecker {
     getWidenedLiteralType(type: Type): Type;
     /** @internal */
     getPromisedTypeOfPromise(promise: Type, errorNode?: Node): Type | undefined;
-    /** @internal */
     getAwaitedType(type: Type): Type | undefined;
     /** @internal */
     isEmptyAnonymousObjectType(type: Type): boolean;

tests/baselines/reference/api/typescript.d.ts

@@ -6070,6 +6070,7 @@ declare namespace ts {
         getBaseTypes(type: InterfaceType): BaseType[];
         getBaseTypeOfLiteralType(type: Type): Type;
         getWidenedType(type: Type): Type;
+        getAwaitedType(type: Type): Type | undefined;
         getReturnTypeOfSignature(signature: Signature): Type;
         getNullableType(type: Type, flags: TypeFlags): Type;
         getNonNullableType(type: Type): Type;