fix(compiler): report errors properly in G3 in certain conditions (#20041)

Condition: static analysis error, given:
- noResolve:true
- generateCodeForLibraries: false
- CompilerHost.getSourceFile throws on non existent files

All of these are true in G3.
PR Close #20041

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

@@ -456,13 +456,13 @@ class AngularCompilerProgram implements Program {
     };
 
 
-    let rootNames = this.rootNames;
+    let rootNames = [...this.rootNames];
     if (this.options.generateCodeForLibraries !== false) {
       // if we should generateCodeForLibraries, never include
       // generated files in the program as otherwise we will
       // ovewrite them and typescript will report the error
       // TS5055: Cannot write file ... because it would overwrite input file.
-      rootNames = this.rootNames.filter(fn => !GENERATED_FILES.test(fn));
+      rootNames = rootNames.filter(fn => !GENERATED_FILES.test(fn));
     }
     if (this.options.noResolve) {
       this.rootNames.forEach(rootName => {