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

src/assembler.h

Index: src/assembler.h
diff --git a/src/assembler.h b/src/assembler.h
index 1a3219db1acf93eea3a4615da10ae791d48d107e..1243adf468cbc91b25db83a58e4cd0732aaa6b07 100644
--- a/src/assembler.h
+++ b/src/assembler.h
@@ -100,6 +100,9 @@ class AssemblerBase: public Malloced {
   // the assembler could clean up internal data structures.
   virtual void AbortedCodeGeneration() { }
 
+  // Debugging
+  void Print();
+
   static const int kMinimalBufferSize = 4*KB;
 
   static void FlushICache(Isolate* isolate, void* start, size_t size);