[wasm] Introduce the --print-wasm-code flag to print wasm code.

src/codegen.cc

Index: src/codegen.cc
diff --git a/src/codegen.cc b/src/codegen.cc
index 251379481512ce080ed8765cf2f94abfb004cd4c..f034051ea39b806ed85ff48506a82ad1904536af 100644
--- a/src/codegen.cc
+++ b/src/codegen.cc
@@ -237,7 +237,8 @@ void CodeGenerator::PrintCode(Handle<Code> code, CompilationInfo* info) {
           ? FLAG_print_builtin_code
           : (FLAG_print_code || (info->IsStub() && FLAG_print_code_stubs) ||
              (info->IsOptimizing() && FLAG_print_opt_code &&
-              info->shared_info()->PassesFilter(FLAG_print_opt_code_filter)));
+              info->shared_info()->PassesFilter(FLAG_print_opt_code_filter)) ||
+             (info->IsWasm() && FLAG_print_wasm_code));
   if (print_code) {
     std::unique_ptr<char[]> debug_name = info->GetDebugName();
     CodeTracer::Scope tracing_scope(info->isolate()->GetCodeTracer());