Fixed build (unused vars in release mode).

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index f39ecad915ba283fe18a7774ad01c855902e1be8..0c907e44ad5889b47b212751a683e5c1c8792202 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -1331,10 +1331,9 @@ void LCodeGen::DoDivI(LDivI* instr) {
   Register dividend = ToRegister(instr->dividend());
   Register divisor = ToRegister(instr->divisor());
   Register remainder = ToRegister(instr->temp());
-  Register result = ToRegister(instr->result());
   ASSERT(dividend.is(rax));
   ASSERT(remainder.is(rdx));
-  ASSERT(result.is(rax));
+  ASSERT(ToRegister(instr->result()).is(rax));
   ASSERT(!divisor.is(rax));
   ASSERT(!divisor.is(rdx));