[ARM] Add support for ARMV6K subtarget (LLVM)

ARMv6K is another layer between ARMV6 and ARMV6T2. This is the LLVM
side of the changes.

ARMV6 family LLVM implementation.

+-------------------------------------+
| ARMV6                               |
+----------------+--------------------+
| ARMV6M (thumb) | ARMV6K (arm,thumb) | <- From ARMV6K and ARMV6M processors
+----------------+--------------------+    have support for hint instructions
| ARMV6T2 (arm,thumb,thumb2)          |    (SEV/WFE/WFI/NOP/YIELD). They can
+-------------------------------------+    be either real or default to NOP.
| ARMV7 (arm,thumb,thumb2)            |    The two processors also use
+-------------------------------------+    different encoding for them.

Patch by Vinicius Tinti.

llvm-svn: 232468
diff --git a/llvm/lib/Target/ARM/ARMSubtarget.h b/llvm/lib/Target/ARM/ARMSubtarget.h
index 64d499a..fc1176d 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.h
+++ b/llvm/lib/Target/ARM/ARMSubtarget.h
@@ -56,13 +56,14 @@
   ARMProcClassEnum ARMProcClass;
 
   /// HasV4TOps, HasV5TOps, HasV5TEOps,
-  /// HasV6Ops, HasV6MOps, HasV6T2Ops, HasV7Ops, HasV8Ops -
+  /// HasV6Ops, HasV6MOps, HasV6KOps, HasV6T2Ops, HasV7Ops, HasV8Ops -
   /// Specify whether target support specific ARM ISA variants.
   bool HasV4TOps;
   bool HasV5TOps;
   bool HasV5TEOps;
   bool HasV6Ops;
   bool HasV6MOps;
+  bool HasV6KOps;
   bool HasV6T2Ops;
   bool HasV7Ops;
   bool HasV8Ops;
@@ -284,6 +285,7 @@
   bool hasV5TEOps() const { return HasV5TEOps; }
   bool hasV6Ops()   const { return HasV6Ops;   }
   bool hasV6MOps()  const { return HasV6MOps;  }
+  bool hasV6KOps()  const { return HasV6KOps; }
   bool hasV6T2Ops() const { return HasV6T2Ops; }
   bool hasV7Ops()   const { return HasV7Ops;  }
   bool hasV8Ops()   const { return HasV8Ops;  }