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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110584 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMSubtarget.h b/lib/Target/ARM/ARMSubtarget.h
index e7d92ed..3f24558 100644
--- a/lib/Target/ARM/ARMSubtarget.h
+++ b/lib/Target/ARM/ARMSubtarget.h
@@ -84,6 +84,10 @@
   /// instructions.
   bool HasT2ExtractPack;
 
+  /// Pref32BitThumb - If true, codegen would prefer 32-bit Thumb instructions
+  /// over 16-bit ones.
+  bool Pref32BitThumb;
+
   /// stackAlignment - The minimum alignment known to hold of the stack frame on
   /// entry to the function and which must be maintained by every function.
   unsigned stackAlignment;
@@ -137,6 +141,7 @@
   bool hasT2ExtractPack() const { return HasT2ExtractPack; }
   bool useVMLx() const {return hasVFP2() && !SlowVMLx; }
   bool isFPBrccSlow() const { return SlowFPBrcc; }
+  bool prefers32BitThumb() const { return Pref32BitThumb; }
 
   bool hasFP16() const { return HasFP16; }