More MSan/ASan annotations.

This change lets us bootstrap LLVM/Clang under ASan and MSan. It contains
fixes for 2 issues:

- X86JIT reads return address from stack, which MSan does not know is
  initialized.
- bugpoint tests run binaries with RLIMIT_AS. This does not work with certain
  Sanitizers.

We are no longer including config.h in Compiler.h with this change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174306 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Support/Allocator.cpp

@@ -104,8 +104,8 @@ void *BumpPtrAllocator::Allocate(size_t Size, size_t Alignment) {
   if (Ptr + Size <= End) {
     CurPtr = Ptr + Size;
     // Update the allocation point of this memory block in MemorySanitizer.
-    // Without this, MemorySanitizer reports for values originating from it will
-    // point to the allocation point of the entire slab.
+    // Without this, MemorySanitizer messages for values originated from here
+    // will point to the allocation of the entire slab.
     __msan_allocated_memory(Ptr, Size);
     return Ptr;
   }