ARM: set default float ABI based on triple.

Clang sets the float-abi target option manually, but no longer
annotates each function with its ABI. This can lead to confusing
mistmatch between "clang -emit-llvm | llc" and normal clang
invocations.

Besides which, gnueabihf actually *is* hard-float. Defaulting to soft
was just perverse.

llvm-svn: 197554
diff --git a/llvm/lib/Target/ARM/ARMSubtarget.h b/llvm/lib/Target/ARM/ARMSubtarget.h
index 42bc155..4893973 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.h
+++ b/llvm/lib/Target/ARM/ARMSubtarget.h
@@ -321,6 +321,11 @@
       TargetTriple.getEnvironment() == Triple::EABIHF;
   }
 
+  bool isTargetHardFloat() const {
+    return TargetTriple.getEnvironment() == Triple::GNUEABIHF ||
+           TargetTriple.getEnvironment() == Triple::EABIHF;
+  }
+
   bool isAPCS_ABI() const { return TargetABI == ARM_ABI_APCS; }
   bool isAAPCS_ABI() const { return TargetABI == ARM_ABI_AAPCS; }