Minor cleanup to the code-completion-point logic suggested by Chris.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@90459 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Lex/Preprocessor.h

@@ -507,7 +507,7 @@ public:
 
   /// \brief Determine if this source location refers into the file
   /// for which we are performing code completion.
-  bool isCodeCompletionFile(SourceLocation FileLoc);
+  bool isCodeCompletionFile(SourceLocation FileLoc) const;
 
   /// Diag - Forwarding function for diagnostics.  This emits a diagnostic at
   /// the specified Token's location, translating the token's start

lib/Basic/SourceManager.cpp

@@ -47,8 +47,7 @@ unsigned ContentCache::getSize() const {
 }
 
 void ContentCache::replaceBuffer(const llvm::MemoryBuffer *B) {
-  if (B == Buffer)
+  assert(B != Buffer);
-    return;
   
   delete Buffer;
   Buffer = B;

lib/Lex/Preprocessor.cpp

@@ -240,7 +240,7 @@ bool Preprocessor::SetCodeCompletionPoint(const FileEntry *File,
   return false;
 }
 
-bool Preprocessor::isCodeCompletionFile(SourceLocation FileLoc) {
+bool Preprocessor::isCodeCompletionFile(SourceLocation FileLoc) const {
   return CodeCompletionFile && FileLoc.isFileID() &&
     SourceMgr.getFileEntryForID(SourceMgr.getFileID(FileLoc))
       == CodeCompletionFile;