release-5.4: Revert PR 56087 (#57850)

src/compiler/checker.ts

@@ -5735,12 +5735,6 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
      * Checks if two symbols, through aliasing and/or merging, refer to the same thing
      */
     function getSymbolIfSameReference(s1: Symbol, s2: Symbol) {
-        if (s1.flags & SymbolFlags.TypeAlias && s2.declarations?.find(isTypeAlias)) {
-            s2 = getDeclaredTypeOfTypeAlias(s2).aliasSymbol || s2;
-        }
-        if (s2.flags & SymbolFlags.TypeAlias && s1.declarations?.find(isTypeAlias)) {
-            s1 = getDeclaredTypeOfTypeAlias(s1).aliasSymbol || s1;
-        }
         if (getMergedSymbol(resolveSymbol(getMergedSymbol(s1))) === getMergedSymbol(resolveSymbol(getMergedSymbol(s2)))) {
             return s1;
         }

tests/baselines/reference/declarationEmitUsingTypeAlias1.errors.txt

@@ -0,0 +1,34 @@
+src/index.ts(3,14): error TS2742: The inferred type of 'foo' cannot be named without a reference to '../node_modules/some-dep/dist/inner'. This is likely not portable. A type annotation is necessary.
+src/index.ts(7,14): error TS2742: The inferred type of 'bar' cannot be named without a reference to '../node_modules/some-dep/dist/inner'. This is likely not portable. A type annotation is necessary.
+
+
+==== node_modules/some-dep/dist/inner.d.ts (0 errors) ====
+    export declare type Other = { other: string };
+    export declare type SomeType = { arg: Other };
+
+==== node_modules/some-dep/dist/index.d.ts (0 errors) ====
+    export type OtherType = import('./inner').Other;
+    export type SomeType = import('./inner').SomeType;
+
+==== node_modules/some-dep/package.json (0 errors) ====
+    {
+      "name": "some-dep",
+      "exports": {
+        ".": "./dist/index.js"
+      }
+    }
+
+==== src/index.ts (2 errors) ====
+    import { SomeType } from "some-dep";
+
+    export const foo = (thing: SomeType) => {
+                 ~~~
+!!! error TS2742: The inferred type of 'foo' cannot be named without a reference to '../node_modules/some-dep/dist/inner'. This is likely not portable. A type annotation is necessary.
+      return thing;
+    };
+
+    export const bar = (thing: SomeType) => {
+                 ~~~
+!!! error TS2742: The inferred type of 'bar' cannot be named without a reference to '../node_modules/some-dep/dist/inner'. This is likely not portable. A type annotation is necessary.
+      return thing.arg;
+    };

tests/baselines/reference/declarationEmitUsingTypeAlias1.js

@@ -39,9 +39,3 @@ var bar = function (thing) {
     return thing.arg;
 };
 exports.bar = bar;
-
-
-//// [index.d.ts]
-import { SomeType } from "some-dep";
-export declare const foo: (thing: SomeType) => import("some-dep").SomeType;
-export declare const bar: (thing: SomeType) => import("some-dep").OtherType;