AArch64: support binutils-like things on arm64_32.

This adds support for the arm64_32 watchOS ABI to LLVM's low level tools,
teaching them about the specific MachO choices and constants needed to
disassemble things.

llvm-svn: 360663
diff --git a/llvm/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp b/llvm/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp
index c260deb..e020a74 100644
--- a/llvm/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp
+++ b/llvm/lib/Target/AArch64/Disassembler/AArch64Disassembler.cpp
@@ -286,11 +286,19 @@
                                        createAArch64ExternalSymbolizer);
   TargetRegistry::RegisterMCSymbolizer(getTheAArch64beTarget(),
                                        createAArch64ExternalSymbolizer);
+  TargetRegistry::RegisterMCDisassembler(getTheAArch64_32Target(),
+                                         createAArch64Disassembler);
+  TargetRegistry::RegisterMCSymbolizer(getTheAArch64_32Target(),
+                                       createAArch64ExternalSymbolizer);
 
   TargetRegistry::RegisterMCDisassembler(getTheARM64Target(),
                                          createAArch64Disassembler);
   TargetRegistry::RegisterMCSymbolizer(getTheARM64Target(),
                                        createAArch64ExternalSymbolizer);
+  TargetRegistry::RegisterMCDisassembler(getTheARM64_32Target(),
+                                         createAArch64Disassembler);
+  TargetRegistry::RegisterMCSymbolizer(getTheARM64_32Target(),
+                                       createAArch64ExternalSymbolizer);
 }
 
 static const unsigned FPR128DecoderTable[] = {