Change -prefer-32bit-thumb to attribute -mattr=+32bit instead to disable more 32-bit to 16-bit optimizations.

llvm-svn: 110584
diff --git a/llvm/lib/Target/ARM/ARM.td b/llvm/lib/Target/ARM/ARM.td
index fa64d6c..e76a47d 100644
--- a/llvm/lib/Target/ARM/ARM.td
+++ b/llvm/lib/Target/ARM/ARM.td
@@ -65,6 +65,9 @@
                                         "true",
                                         "Use NEON for single precision FP">;
 
+// Disable 32-bit to 16-bit narrowing for experimentation.
+def FeaturePref32BitThumb : SubtargetFeature<"32bit", "Pref32BitThumb", "true",
+                                             "Prefer 32-bit Thumb instrs">;
 
 //===----------------------------------------------------------------------===//
 // ARM Processors supported.