[X87] [crankshaft] Fix Math.max(-0, 0) bug.

src/crankshaft/x87/lithium-codegen-x87.cc

Index: src/crankshaft/x87/lithium-codegen-x87.cc
diff --git a/src/crankshaft/x87/lithium-codegen-x87.cc b/src/crankshaft/x87/lithium-codegen-x87.cc
index 2648681b42e0c8bf21c67f958101aa1451e47044..a51c33f0f1cc44ea529e8af65c1db366557d27ca 100644
--- a/src/crankshaft/x87/lithium-codegen-x87.cc
+++ b/src/crankshaft/x87/lithium-codegen-x87.cc
@@ -1969,8 +1969,8 @@ void LCodeGen::DoMathMinMax(LMathMinMax* instr) {
       __ pop(scratch_reg);  // restore esp
     } else {
       // Since we operate on +0 and/or -0, addsd and andsd have the same effect.
-      X87Fxch(left_reg);
-      __ fadd(1);
+      // Should put the result in stX0
+      __ fadd_i(1);
     }
     __ jmp(&return_left, Label::kNear);
 
@@ -1981,7 +1981,6 @@ void LCodeGen::DoMathMinMax(LMathMinMax* instr) {
     __ j(parity_even, &return_left, Label::kNear);  // left == NaN.
 
     __ bind(&return_right);
-    X87Fxch(left_reg);
     X87Mov(left_reg, right_reg);
 
     __ bind(&return_left);