some minor cleanups to SourceManager, and eliminate the 
SourceManager::getBuffer(SourceLocation) method.

llvm-svn: 62494
diff --git a/clang/lib/Basic/SourceManager.cpp b/clang/lib/Basic/SourceManager.cpp
index f793c97..b053b16 100644
--- a/clang/lib/Basic/SourceManager.cpp
+++ b/clang/lib/Basic/SourceManager.cpp
@@ -184,7 +184,7 @@
 /// data for the specified location.
 std::pair<const char*, const char*> 
 SourceManager::getBufferData(SourceLocation Loc) const {
-  const llvm::MemoryBuffer *Buf = getBuffer(Loc);
+  const llvm::MemoryBuffer *Buf = getBuffer(getCanonicalFileID(Loc));
   return std::make_pair(Buf->getBufferStart(), Buf->getBufferEnd());
 }