Unify the two CRC implementations

David added the JamCRC implementation in r246590. More recently, Eugene
added a CRC-32 implementation in r357901, which falls back to zlib's
crc32 function if present.

These checksums are essentially the same, so having multiple
implementations seems unnecessary. This replaces the CRC-32
implementation with the simpler one from JamCRC, and implements the
JamCRC interface in terms of CRC-32 since this means it can use zlib's
implementation when available, saving a few bytes and potentially making
it faster.

JamCRC took an ArrayRef<char> argument, and CRC-32 took a StringRef.
This patch changes it to ArrayRef<uint8_t> which I think is the best
choice, and simplifies a few of the callers nicely.

Differential revision: https://reviews.llvm.org/D68570

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@374148 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AST/MicrosoftMangle.cpp

@@ -27,11 +27,11 @@
 #include "clang/Basic/DiagnosticOptions.h"
 #include "clang/Basic/TargetInfo.h"
 #include "llvm/ADT/StringExtras.h"
-#include "llvm/Support/JamCRC.h"
-#include "llvm/Support/xxhash.h"
+#include "llvm/Support/CRC.h"
 #include "llvm/Support/MD5.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/StringSaver.h"
+#include "llvm/Support/xxhash.h"
 
 using namespace clang;