Centralize where we update the source file contents in SourceManager::GetFile() in case APIs are called that don't update the source.
The following functions were the only functions that updates the source file:
SourceManager::File::DisplaySourceLines()
SourceManager::File::FindLinesMatchingRegex()
But there we API calls that were using the SourceManager::File and asking it questions, like "is line 12 valid" and that might respond incorrectly if the source file had been updated.
<rdar://problem/
21269402>
llvm-svn: 243551