Implement more intrinisification for x64 (not as inlined code but as header of the target).

runtime/vm/assembler_x64.h

Index: runtime/vm/assembler_x64.h
===================================================================
--- runtime/vm/assembler_x64.h	(revision 9572)
+++ runtime/vm/assembler_x64.h	(working copy)
@@ -444,10 +444,24 @@
   void leave();
   void ret();
 
+  void movmskpd(Register dst, XmmRegister src);
+
   void sqrtsd(XmmRegister dst, XmmRegister src);
 
   void xorpd(XmmRegister dst, const Address& src);
+  void xorpd(XmmRegister dst, XmmRegister src);
 
+  void fldl(const Address& src);
+  void fstpl(const Address& dst);
+
+  void fildl(const Address& src);
+
+  void fincstp();
+  void ffree(intptr_t value);
+
+  void fsin();
+  void fcos();
+
   // 'size' indicates size in bytes and must be in the range 1..8.
   void nop(int size = 1);
   void int3();