Forward WrapperFrontendAction::shouldEraseOutputFiles()

Per the documentation, this class is supposed to forward every virtual
method, but we had missed on (shouldEraseOutputFiles). This fixes using
a wrapped frontend action over the PCH generator when using
-fallow-pch-with-compiler-errors. I do not think any upstream wrapper
actions can test this.

Differential Revision: https://reviews.llvm.org/D77180

rdar://61110294

clang/include/clang/Frontend/FrontendAction.h

@@ -312,6 +312,7 @@ protected:
   bool BeginSourceFileAction(CompilerInstance &CI) override;
   void ExecuteAction() override;
   void EndSourceFileAction() override;
+  bool shouldEraseOutputFiles() override;
 
 public:
   /// Construct a WrapperFrontendAction from an existing action, taking

clang/lib/Frontend/FrontendAction.cpp

@@ -1081,6 +1081,9 @@ void WrapperFrontendAction::ExecuteAction() {
 void WrapperFrontendAction::EndSourceFileAction() {
   WrappedAction->EndSourceFileAction();
 }
+bool WrapperFrontendAction::shouldEraseOutputFiles() {
+  return WrappedAction->shouldEraseOutputFiles();
+}
 
 bool WrapperFrontendAction::usesPreprocessorOnly() const {
   return WrappedAction->usesPreprocessorOnly();