Add a special ARM trap encoding for NaCl.
More details in this thread: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20130128/163783.html

Patch by JF Bastien

llvm-svn: 173943
diff --git a/llvm/lib/Target/ARM/ARMSubtarget.h b/llvm/lib/Target/ARM/ARMSubtarget.h
index 64878cd..33efabf 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.h
+++ b/llvm/lib/Target/ARM/ARMSubtarget.h
@@ -156,6 +156,9 @@
   /// and such) instructions in Thumb2 code.
   bool Thumb2DSP;
 
+  /// NaCl TRAP instruction is generated instead of the regular TRAP.
+  bool UseNaClTrap;
+
   /// 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;
@@ -241,6 +244,7 @@
   bool hasRAS() const { return HasRAS; }
   bool hasMPExtension() const { return HasMPExtension; }
   bool hasThumb2DSP() const { return Thumb2DSP; }
+  bool useNaClTrap() const { return UseNaClTrap; }
 
   bool hasFP16() const { return HasFP16; }
   bool hasD16() const { return HasD16; }