fix(compiler): don’t use ng:// in AOT source maps, and never point to the original source file

This is important to not confuse users nor downstream tools that
consume our source maps. For generated content for which we don’t
have an original source file, we use the generated file now.

Fixes #19538

packages/compiler-cli/src/transformers/compiler_host.ts

@@ -287,7 +287,7 @@ export class TsCompilerAotCompilerTypeCheckHostAdapter extends
           `Invalid Argument: Expected a GenerateFile with statements. ${genFile.genFileUrl}`);
     }
     const {sourceText, context} = this.emitter.emitStatementsAndContext(
-        genFile.srcFileUrl, genFile.genFileUrl, genFile.stmts, /* preamble */ '',
+        genFile.genFileUrl, genFile.stmts, /* preamble */ '',
         /* emitSourceMaps */ false);
     const sf = ts.createSourceFile(
         genFile.genFileUrl, sourceText, this.options.target || ts.ScriptTarget.Latest);