Use the correct version of movq for ExternalReference in X64

src/x64/assembler-x64.h

Index: src/x64/assembler-x64.h
diff --git a/src/x64/assembler-x64.h b/src/x64/assembler-x64.h
index fd1e1e75d55db829fb6f1723543c8fab7611ada6..f462b7eb5e7e0427a78e1a62052bb52cfd320b7a 100644
--- a/src/x64/assembler-x64.h
+++ b/src/x64/assembler-x64.h
@@ -723,7 +723,6 @@ class Assembler : public AssemblerBase {
   // All 64-bit immediates must have a relocation mode.
   void movq(Register dst, void* ptr, RelocInfo::Mode rmode);
   void movq(Register dst, int64_t value, RelocInfo::Mode rmode);
-  void movq(Register dst, const char* s, RelocInfo::Mode rmode);
   // Moves the address of the external reference into the register.
   void movq(Register dst, ExternalReference ext);
   void movq(Register dst, Handle<Object> handle, RelocInfo::Mode rmode);
@@ -1474,7 +1473,7 @@ class Assembler : public AssemblerBase {
   void emit(byte x) { *pc_++ = x; }
   inline void emitl(uint32_t x);
   inline void emitp(void* x, RelocInfo::Mode rmode);
-  inline void emitq(uint64_t x, RelocInfo::Mode rmode);
+  inline void emitq(uint64_t x);
   inline void emitw(uint16_t x);
   inline void emit_code_target(Handle<Code> target,
                                RelocInfo::Mode rmode,