Emit source positions in deopt comments, too.

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 300572a740d0665d23beead0f0193825c54891c9..0357cc304ae731ad5eb85db5a3dab84aa8295649 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -899,7 +899,8 @@ void LCodeGen::DeoptimizeIf(Condition condition, LInstruction* instr,
     __ stop("trap_on_deopt", condition);
   }
 
-  Deoptimizer::Reason reason(instr->Mnemonic(), detail);
+  Deoptimizer::Reason reason(instr->hydrogen_value()->position().raw(),
+                             instr->Mnemonic(), detail);
   DCHECK(info()->IsStub() || frame_is_built_);
   // Go through jump table if we need to handle condition, build frame, or
   // restore caller doubles.