[PATCH] Annotate BumpPtrAllocator for MemorySanitizer

[Kostya Serebryany]

  LGTM


================
Comment at: lib/Support/Allocator.cpp:106
@@ -104,2 +105,3 @@
     CurPtr = Ptr + Size;
+    __msan_allocated_memory(Ptr, Size);
     return Ptr;
----------------
maybe add a comment why we need this?


http://llvm-reviews.chandlerc.com/D336