ARMv7k: base ABI decision on v7k Arch rather than watchos OS.

Various bits we want to use the new ABI actually compile with "-arch armv7k
-miphoneos-version-min=9.0". Not ideal, but also not ridiculous given how
slices work.

llvm-svn: 258975
diff --git a/llvm/lib/Target/ARM/ARMSubtarget.h b/llvm/lib/Target/ARM/ARMSubtarget.h
index efa3196..e6fa378 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.h
+++ b/llvm/lib/Target/ARM/ARMSubtarget.h
@@ -390,6 +390,7 @@
   bool isTargetDarwin() const { return TargetTriple.isOSDarwin(); }
   bool isTargetIOS() const { return TargetTriple.isiOS(); }
   bool isTargetWatchOS() const { return TargetTriple.isWatchOS(); }
+  bool isTargetWatchABI() const { return TargetTriple.isWatchABI(); }
   bool isTargetLinux() const { return TargetTriple.isOSLinux(); }
   bool isTargetNaCl() const { return TargetTriple.isOSNaCl(); }
   bool isTargetNetBSD() const { return TargetTriple.isOSNetBSD(); }