Move MainFileName option variable into CodeGenOptions instead of LangOptions.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@90051 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 558bb5b..317da7e 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -95,10 +95,10 @@
   // file at a time.
   bool isMain = false;
   const LangOptions &LO = M->getLangOptions();
-  const char *MainFileName = LO.getMainFileName();
+  const CodeGenOptions &CGO = M->getCodeGenOpts();
   if (isMainCompileUnitCreated == false) {
-    if (MainFileName) {
-      if (!strcmp(AbsFileName.getLast().c_str(), MainFileName))
+    if (!CGO.MainFileName.empty()) {
+      if (AbsFileName.getLast() == CGO.MainFileName)
         isMain = true;
     } else {
       if (Loc.isValid() && SM.isFromMainFile(Loc))