When building a module on-demand, clear out the "non-modular" language
and preprocessor options (such as macro definitions) first.

llvm-svn: 139638
diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index f39b119..ece9cd8 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -654,6 +654,9 @@
   // Construct a compiler invocation for creating this module.
   llvm::IntrusiveRefCntPtr<CompilerInvocation> Invocation
     (new CompilerInvocation(ImportingInstance.getInvocation()));
+  Invocation->getLangOpts().resetNonModularOptions();
+  Invocation->getPreprocessorOpts().resetNonModularOptions();
+  
   FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
   FrontendOpts.OutputFile = ModuleFile.str();
   FrontendOpts.DisableFree = false;