Move -undef flag into PreprocessorInitOptions

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@86047 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/InitPreprocessor.cpp b/lib/Frontend/InitPreprocessor.cpp
index ec5c106..3a54d1d 100644
--- a/lib/Frontend/InitPreprocessor.cpp
+++ b/lib/Frontend/InitPreprocessor.cpp
@@ -443,8 +443,7 @@
 /// environment ready to process a single file. This returns true on error.
 ///
 bool clang::InitializePreprocessor(Preprocessor &PP,
-                                   const PreprocessorInitOptions &InitOpts,
-                                   bool undef_macros) {
+                                   const PreprocessorInitOptions &InitOpts) {
   std::vector<char> PredefineBuffer;
 
   const char *LineDirective = "# 1 \"<built-in>\" 3\n";
@@ -452,7 +451,7 @@
                          LineDirective, LineDirective+strlen(LineDirective));
 
   // Install things like __POWERPC__, __GNUC__, etc into the macro table.
-  if (!undef_macros)
+  if (InitOpts.getUsePredefines())
     InitializePredefinedMacros(PP.getTargetInfo(), PP.getLangOptions(),
                                PredefineBuffer);