[builtins] Make Math.max and Math.min fast by default.

src/x64/macro-assembler-x64.h

Index: src/x64/macro-assembler-x64.h
diff --git a/src/x64/macro-assembler-x64.h b/src/x64/macro-assembler-x64.h
index 695e243c18d2c90ddf0c67f5086b07d907b94e1d..85b795e9ff627e662572435b7a6cbb92eef25d10 100644
--- a/src/x64/macro-assembler-x64.h
+++ b/src/x64/macro-assembler-x64.h
@@ -427,6 +427,12 @@ class MacroAssembler: public Assembler {
   void SmiToInteger64(Register dst, Register src);
   void SmiToInteger64(Register dst, const Operand& src);
 
+  // Convert smi to double.
+  void SmiToDouble(XMMRegister dst, Register src) {
+    SmiToInteger32(kScratchRegister, src);
+    Cvtlsi2sd(dst, kScratchRegister);
+  }
+
   // Multiply a positive smi's integer value by a power of two.
   // Provides result as 64-bit integer value.
   void PositiveSmiTimesPowerOfTwoToInteger64(Register dst,