Add substarget feature for FP16

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98503 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARM.td b/lib/Target/ARM/ARM.td
index 7033861..bbb1dbd 100644
--- a/lib/Target/ARM/ARM.td
+++ b/lib/Target/ARM/ARM.td
@@ -40,6 +40,8 @@
                                    "Enable NEON instructions">;
 def FeatureThumb2 : SubtargetFeature<"thumb2", "ThumbMode", "Thumb2",
                                      "Enable Thumb2 instructions">;
+def FeatureFP16   : SubtargetFeature<"fp16", "HasFP16", "true",
+                                     "Enable half-precision floating point">;
 
 //===----------------------------------------------------------------------===//
 // ARM Processors supported.