Split isFromMainFile into two functions.

Basically, isInMainFile considers line markers, and isWrittenInMainFile
doesn't.  Distinguishing between the two is useful when dealing with
files which are preprocessed files or rewritten with -frewrite-includes
(so we don't, for example, print useless warnings).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188968 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/VerifyDiagnosticConsumer.cpp b/lib/Frontend/VerifyDiagnosticConsumer.cpp
index efe6005..f555529 100644
--- a/lib/Frontend/VerifyDiagnosticConsumer.cpp
+++ b/lib/Frontend/VerifyDiagnosticConsumer.cpp
@@ -628,11 +628,11 @@
   while (DiagnosticLoc.isMacroID())
     DiagnosticLoc = SM.getImmediateMacroCallerLoc(DiagnosticLoc);
 
-  if (SM.isFromSameFile(DirectiveLoc, DiagnosticLoc))
+  if (SM.isWrittenInSameFile(DirectiveLoc, DiagnosticLoc))
     return true;
 
   const FileEntry *DiagFile = SM.getFileEntryForID(SM.getFileID(DiagnosticLoc));
-  if (!DiagFile && SM.isFromMainFile(DirectiveLoc))
+  if (!DiagFile && SM.isWrittenInMainFile(DirectiveLoc))
     return true;
 
   return (DiagFile == SM.getFileEntryForID(SM.getFileID(DirectiveLoc)));