Rename SourceManager::createFileIDForMemBuffer()

It makes more sense to just overload createFileID().

Gardening only.

llvm-svn: 209002
diff --git a/clang/lib/Lex/Preprocessor.cpp b/clang/lib/Lex/Preprocessor.cpp
index d263e7d2..fec0d5b 100644
--- a/clang/lib/Lex/Preprocessor.cpp
+++ b/clang/lib/Lex/Preprocessor.cpp
@@ -479,7 +479,7 @@
   llvm::MemoryBuffer *SB =
     llvm::MemoryBuffer::getMemBufferCopy(Predefines, "<built-in>");
   assert(SB && "Cannot create predefined source buffer");
-  FileID FID = SourceMgr.createFileIDForMemBuffer(SB);
+  FileID FID = SourceMgr.createFileID(SB);
   assert(!FID.isInvalid() && "Could not create FileID for predefines?");
   setPredefinesFileID(FID);