Emit source positions in deopt comments, too.

src/x87/lithium-codegen-x87.cc

Index: src/x87/lithium-codegen-x87.cc
diff --git a/src/x87/lithium-codegen-x87.cc b/src/x87/lithium-codegen-x87.cc
index 690ebcce477bfe54fe103dfd6c17239e1087c7d6..ed4755b995cc319fb57958c6c9f1e30ffb6010bc 100644
--- a/src/x87/lithium-codegen-x87.cc
+++ b/src/x87/lithium-codegen-x87.cc
@@ -1148,7 +1148,8 @@ void LCodeGen::DeoptimizeIf(Condition cc, LInstruction* instr,
     __ bind(&done);
   }
 
-  Deoptimizer::Reason reason(instr->Mnemonic(), detail);
+  Deoptimizer::Reason reason(instr->hydrogen_value()->position().raw(),
+                             instr->Mnemonic(), detail);
   DCHECK(info()->IsStub() || frame_is_built_);
   if (cc == no_condition && frame_is_built_) {
     DeoptComment(reason);