Report error if codegen tries to instantiate a ARM target when the cpu does support it. e.g. cortex-m* processors.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110798 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMSubtarget.h b/lib/Target/ARM/ARMSubtarget.h
index c5b3402..ad9fc11 100644
--- a/lib/Target/ARM/ARMSubtarget.h
+++ b/lib/Target/ARM/ARMSubtarget.h
@@ -63,6 +63,9 @@
   /// ThumbMode - Indicates supported Thumb version.
   ThumbTypeEnum ThumbMode;
 
+  /// NoARM - True if subtarget does not support ARM mode execution.
+  bool NoARM;
+
   /// PostRAScheduler - True if using post-register-allocation scheduler.
   bool PostRAScheduler;
 
@@ -136,6 +139,8 @@
   bool hasV6T2Ops() const { return ARMArchVersion >= V6T2; }
   bool hasV7Ops()   const { return ARMArchVersion >= V7A;  }
 
+  bool hasARMOps() const { return !NoARM; }
+
   bool hasVFP2() const { return ARMFPUType >= VFPv2; }
   bool hasVFP3() const { return ARMFPUType >= VFPv3; }
   bool hasNEON() const { return ARMFPUType >= NEON;  }