fix(@angular/build): warn when using both isolatedModules and `emit…

…DecoratorMetadata`

If both the `isolatedModules` and `emitDecoratorMetadata` Typescript
options are enabled within a project, a warning will now be issued
explaining that not all metadata may be emitting for each decorator.
Isolated modules may not have access to non-local type information
that would otherwise be needed for complete metadata emit.

The `emitDecoratorMetadata` option is not required by Angular and can cause
runtime errors due to its underlying implementation when used with
ES2015+ output. The option is only compatible with the experimental
decorators and cannot be used with standard decorators. New Angular
projects also do not enable this option.

(cherry picked from commit 61e8185)

packages/angular/build/src/tools/esbuild/angular/compiler-plugin.ts

@@ -689,6 +689,20 @@ function createCompilerOptionsTransformer(
       });
     }
 
+    if (compilerOptions.isolatedModules && compilerOptions.emitDecoratorMetadata) {
+      setupWarnings?.push({
+        text: `TypeScript compiler option 'isolatedModules' may prevent the 'emitDecoratorMetadata' option from emitting all metadata.`,
+        location: null,
+        notes: [
+          {
+            text:
+              `The 'emitDecoratorMetadata' option is not required by Angular` +
+              'and can be removed if not explictly required by the project.',
+          },
+        ],
+      });
+    }
+
     // Synchronize custom resolve conditions.
     // Set if using the supported bundler resolution mode (bundler is the default in new projects)
     if (compilerOptions.moduleResolution === 100 /* ModuleResolutionKind.Bundler */) {