perf(ngcc): do not copy files that have been processed (#40429)

When using the `NewEntryPointWriter`, we must copy over all files from the
entry-point bundle to the new entry-point. But since we are going to
write out the modified files directly, there is no need to copy those.
This commit skips copying the files that have been modified.

PR Close #40429

packages/compiler-cli/ngcc/src/writing/new_entry_point_file_writer.ts

@@ -40,7 +40,7 @@ export class NewEntryPointFileWriter extends InPlaceFileWriter {
     // The new folder is at the root of the overall package
     const entryPoint = bundle.entryPoint;
     const ngccFolder = this.fs.join(entryPoint.packagePath, NGCC_DIRECTORY);
-    this.copyBundle(bundle, entryPoint.packagePath, ngccFolder);
+    this.copyBundle(bundle, entryPoint.packagePath, ngccFolder, transformedFiles);
     transformedFiles.forEach(file => this.writeFile(file, entryPoint.packagePath, ngccFolder));
     this.updatePackageJson(entryPoint, formatProperties, ngccFolder);
   }
@@ -67,9 +67,14 @@ export class NewEntryPointFileWriter extends InPlaceFileWriter {
   }
 
   protected copyBundle(
-      bundle: EntryPointBundle, packagePath: AbsoluteFsPath, ngccFolder: AbsoluteFsPath) {
+      bundle: EntryPointBundle, packagePath: AbsoluteFsPath, ngccFolder: AbsoluteFsPath,
+      transformedFiles: FileToWrite[]) {
+    const doNotCopy = new Set(transformedFiles.map(f => f.path));
     bundle.src.program.getSourceFiles().forEach(sourceFile => {
       const originalPath = absoluteFromSourceFile(sourceFile);
+      if (doNotCopy.has(originalPath)) {
+        return;
+      }
       const relativePath = this.fs.relative(packagePath, originalPath);
       const isInsidePackage = isLocalRelativePath(relativePath);
       if (!sourceFile.isDeclarationFile && isInsidePackage) {