MIPS: [turbofan] Support for %_DoubleHi, %_DoubleLo and %_ConstructDouble.

src/mips64/macro-assembler-mips64.h

Index: src/mips64/macro-assembler-mips64.h
diff --git a/src/mips64/macro-assembler-mips64.h b/src/mips64/macro-assembler-mips64.h
index 3d428f77766a4676bf530936d5be85f88286dc27..3c1c2b0a50346e5071af8723cbdd54285385ce65 100644
--- a/src/mips64/macro-assembler-mips64.h
+++ b/src/mips64/macro-assembler-mips64.h
@@ -262,10 +262,16 @@ class MacroAssembler: public Assembler {
     mfhc1(dst_high, src);
   }
 
+  inline void FmoveHigh(FPURegister dst, Register src_high) {
+    mthc1(src_high, dst);
+  }
+
   inline void FmoveLow(Register dst_low, FPURegister src) {
     mfc1(dst_low, src);
   }
 
+  void FmoveLow(FPURegister dst, Register src_low);
+
   inline void Move(FPURegister dst, Register src_low, Register src_high) {
     mtc1(src_low, dst);
     mthc1(src_high, dst);