[assembler] Introduce proper AssemblerBase::Print() for improved debuggability.

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 8cee722dfbf94165d399a1e309b80436fe31079a..3b145f5b38e03942faa3f94447a5164b8765aa36 100644
--- a/src/x64/assembler-x64.h
+++ b/src/x64/assembler-x64.h
@@ -1614,9 +1614,6 @@ class Assembler : public AssemblerBase {
   void rorxl(Register dst, Register src, byte imm8);
   void rorxl(Register dst, const Operand& src, byte imm8);
 
-  // Debugging
-  void Print();
-
   // Check the code size generated from label to here.
   int SizeOfCodeGeneratedSince(Label* label) {
     return pc_offset() - label->pos();