[wasm] Add code printing for native wasm code

This makes --print-code and --print-wasm-code also print code emitted
on the native wasm heap.
It also extends code printing to include the code kind and the index.

R=mtrofin@chromium.org

Change-Id: I39c23f4b65168c059f23477ec5d264924ca83e82
Reviewed-on: https://chromium-review.googlesource.com/831987Reviewed-by: Mircea Trofin <mtrofin@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50166}

src/compiler/wasm-compiler.cc

@@ -5066,6 +5066,15 @@ WasmCodeWrapper WasmCompilationUnit::FinishTurbofanCompilation(
              codegen_ms);
     }
 
+#ifdef ENABLE_DISASSEMBLER
+    if (FLAG_print_code || FLAG_print_wasm_code) {
+      // TODO(wasm): Use proper log files, here and elsewhere.
+      PrintF("--- Native Wasm code ---\n");
+      code->Print(isolate_);
+      PrintF("--- End code ---\n");
+    }
+#endif
+
     Handle<ByteArray> source_positions =
         tf_.job_->compilation_info()->wasm_code_desc()->source_positions_table;
     MaybeHandle<HandlerTable> handler_table =

src/wasm/wasm-code-manager.cc

@@ -180,14 +180,18 @@ void WasmCode::ResetTrapHandlerIndex() { trap_handler_index_ = -1; }
 // Disassembler::Decode.
 void WasmCode::Disassemble(Isolate* isolate, const char* name,
                            std::ostream& os) const {
-  os << name << std::endl;
+  if (name) os << name << std::endl;
   Disassembler::Decode(isolate, &os, instructions().start(),
                        instructions().end(), nullptr);
 }
 
 void WasmCode::Print(Isolate* isolate) const {
   OFStream os(stdout);
-  Disassemble(isolate, "", os);
+  if (index_.IsJust()) {
+    os << "index: " << index_.FromJust() << "\n";
+  }
+  os << "kind: " << GetWasmCodeKindAsString(kind_) << "\n";
+  Disassemble(isolate, nullptr, os);
 }
 
 const char* GetWasmCodeKindAsString(WasmCode::Kind kind) {