AArch64: update Clang for merged arm64/aarch64 triples.

The main subtlety here is that the Darwin tools still need to be given "-arch
arm64" rather than "-arch aarch64". Fortunately this already goes via a custom
function to handle weird edge-cases in other architectures, and it tested.

I removed a few arm64_be tests because that really isn't an interesting thing
to worry about. No-one using big-endian is also referring to the target as
arm64 (at least as far as toolchains go). Mostly they date from when arm64 was
a separate target and we *did* need a parallel name simply to test it at all.
Now aarch64_be is sufficient.

llvm-svn: 213744
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 66be962..5128df8 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -342,8 +342,6 @@
         break;
       case llvm::Triple::aarch64:
       case llvm::Triple::aarch64_be:
-      case llvm::Triple::arm64:
-      case llvm::Triple::arm64_be:
         if (CheckAArch64BuiltinFunctionCall(BuiltinID, TheCall))
           return ExprError();
         break;
@@ -468,8 +466,7 @@
     QualType RHSTy = RHS.get()->getType();
 
     llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch();
-    bool IsPolyUnsigned =
-        Arch == llvm::Triple::aarch64 || Arch == llvm::Triple::arm64;
+    bool IsPolyUnsigned = Arch == llvm::Triple::aarch64;
     bool IsInt64Long =
         Context.getTargetInfo().getInt64Type() == TargetInfo::SignedLong;
     QualType EltTy =