Implement X87 stack tracking and x87 multiplication

src/ia32/lithium-gap-resolver-ia32.cc

Index: src/ia32/lithium-gap-resolver-ia32.cc
diff --git a/src/ia32/lithium-gap-resolver-ia32.cc b/src/ia32/lithium-gap-resolver-ia32.cc
index 86bfe2fbf28f7279533222ba770a026b0c9f3816..505ce60aca7441969999eb0c22efc3310a2c4ebc 100644
--- a/src/ia32/lithium-gap-resolver-ia32.cc
+++ b/src/ia32/lithium-gap-resolver-ia32.cc
@@ -342,10 +342,10 @@ void LGapResolver::EmitMove(int index) {
     } else {
       // load from the register onto the stack, store in destination, which must
       // be a double stack slot in the non-SSE2 case.
-      ASSERT(source->index() == 0);  // source is on top of the stack
       ASSERT(destination->IsDoubleStackSlot());
       Operand dst = cgen_->ToOperand(destination);
-      cgen_->ReadX87Operand(dst);
+      X87Register src = cgen_->ToX87Register(source);
+      cgen_->X87Mov(dst, src);
     }
   } else if (source->IsDoubleStackSlot()) {
     if (CpuFeatures::IsSupported(SSE2)) {
@@ -378,10 +378,8 @@ void LGapResolver::EmitMove(int index) {
         __ mov(dst1, tmp);
       } else {
         Operand src = cgen_->ToOperand(source);
-        if (cgen_->X87StackNonEmpty()) {
-          cgen_->PopX87();
-        }
-        cgen_->PushX87DoubleOperand(src);
+        X87Register dst = cgen_->ToX87Register(destination);
+        cgen_->X87Mov(dst, src);
       }
     }
   } else {