Move out MCParser changes

Author: cyndyishida

llvm/lib/MC/MCParser/DarwinAsmParser.cpp

@@ -1147,15 +1147,13 @@ static Triple::OSType getOSTypeFromPlatform(MachO::PlatformType Type) {
   case MachO::PLATFORM_IOS:     return Triple::IOS;
   case MachO::PLATFORM_TVOS:    return Triple::TvOS;
   case MachO::PLATFORM_WATCHOS: return Triple::WatchOS;
-  case MachO::PLATFORM_XROS:    return Triple::XROS;
   case MachO::PLATFORM_BRIDGEOS:         /* silence warning */ break;
   case MachO::PLATFORM_DRIVERKIT:
     return Triple::DriverKit;
   case MachO::PLATFORM_MACCATALYST: return Triple::IOS;
   case MachO::PLATFORM_IOSSIMULATOR:     /* silence warning */ break;
   case MachO::PLATFORM_TVOSSIMULATOR:    /* silence warning */ break;
   case MachO::PLATFORM_WATCHOSSIMULATOR: /* silence warning */ break;
-  case MachO::PLATFORM_XROS_SIMULATOR:   /* silence warning */ break;
   }
   llvm_unreachable("Invalid mach-o platform type");
 }

llvm/lib/TargetParser/Triple.cpp

@@ -1264,6 +1264,8 @@ bool Triple::getMacOSXVersion(VersionTuple &Version) const {
     // IOS.
     Version = VersionTuple(10, 4);
     break;
+  case XROS:
+    llvm_unreachable("OSX version isn't relevant for xrOS");
   case DriverKit:
     llvm_unreachable("OSX version isn't relevant for DriverKit");
   }
@@ -1318,6 +1320,8 @@ VersionTuple Triple::getWatchOSVersion() const {
   }
   case IOS:
     llvm_unreachable("conflicting triple info");
+  case XROS:
+    llvm_unreachable("watchOS version isn't relevant for xrOS");
   case DriverKit:
     llvm_unreachable("DriverKit doesn't have a WatchOS version");
   }