[interpreter] Print bytecode handlers name with --trace-ignition-codegen

When using --trace-ignition-codegen, the name for each bytecode handler is
missing. The reason is that we find the name of a bytecode by looking up the
code object entry in the interpreter's dispatch table, which is not yet
populated at this point.

BUG=

Review-Url: https://codereview.chromium.org/2771503004
Cr-Commit-Position: refs/heads/master@{#44068}

src/interpreter/interpreter-generator.cc

@@ -154,7 +154,7 @@ Handle<Code> GenerateBytecodeHandler(Isolate* isolate, Bytecode bytecode,
 #ifdef ENABLE_DISASSEMBLER
   if (FLAG_trace_ignition_codegen) {
     OFStream os(stdout);
-    code->Disassemble(nullptr, os);
+    code->Disassemble(Bytecodes::ToString(bytecode), os);
     os << std::flush;
   }
 #endif  // ENABLE_DISASSEMBLER