Import MutableArrayRef into clang namespace.

llvm-svn: 211988
diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index 0daf736..e6a6d09 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -598,8 +598,8 @@
     // in the range of ASCII characters 'A' to 'P'.
     // The number 0x123450 would be encoded as 'BCDEFA'
     char EncodedNumberBuffer[sizeof(uint64_t) * 2];
-    llvm::MutableArrayRef<char> BufferRef(EncodedNumberBuffer);
-    llvm::MutableArrayRef<char>::reverse_iterator I = BufferRef.rbegin();
+    MutableArrayRef<char> BufferRef(EncodedNumberBuffer);
+    MutableArrayRef<char>::reverse_iterator I = BufferRef.rbegin();
     for (; Value != 0; Value >>= 4)
       *I++ = 'A' + (Value & 0xf);
     Out.write(I.base(), I - BufferRef.rbegin());