[turbofan] Enable concurrent (re)compilation.

src/compiler/wasm-compiler.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/wasm-compiler.h"
 
 #include "src/isolate-inl.h"
 
 #include "src/base/platform/elapsed-timer.h"
 #include "src/base/platform/platform.h"
@@ skipping 2950 matching lines @@
   if (func_name.is_empty()) {
     if (debugging) {
       buffer = Vector<char>::New(128);
       int chars = SNPrintF(buffer, "WASM_function_#%d", function.func_index);
       func_name = Vector<const char>::cast(buffer.SubVector(0, chars));
     } else {
       func_name = ArrayVector("wasm");
     }
   }
   CompilationInfo info(func_name, isolate, jsgraph->graph()->zone(), flags);
-  compiler::ZonePool::Scope pipeline_zone_scope(&zone_pool);
-  Pipeline pipeline(&info);
-  pipeline.InitializeWasmCompilation(pipeline_zone_scope.zone(), &zone_pool,
-                                     jsgraph->graph(), source_positions);
-  Handle<Code> code;
-  if (pipeline.ExecuteWasmCompilation(descriptor)) {
-    code = pipeline.FinalizeWasmCompilation(descriptor);
-  } else {
-    code = Handle<Code>::null();
+  base::SmartPointer<OptimizedCompileJob> job(Pipeline::NewWasmCompilationJob(
+      &info, jsgraph->graph(), descriptor, source_positions));
+  Handle<Code> code = Handle<Code>::null();
+  if (job->OptimizeGraph() == OptimizedCompileJob::SUCCEEDED &&
+      job->GenerateCode() == OptimizedCompileJob::SUCCEEDED) {
+    code = info.code();
   }
 
   buffer.Dispose();
   if (!code.is_null()) {
     RecordFunctionCompilation(Logger::FUNCTION_TAG, &info, "WASM_function",
                               function.func_index,
                               module_env->module->GetName(
                                   function.name_offset, function.name_length));
   }
 
   if (FLAG_trace_wasm_decode_time) {
     double compile_ms = compile_timer.Elapsed().InMillisecondsF();
     PrintF(
         "wasm-compile ok: %d bytes, %0.3f ms decode, %d nodes, %0.3f ms "
         "compile\n",
         static_cast<int>(function.code_end_offset - function.code_start_offset),
         decode_ms, static_cast<int>(jsgraph->graph()->NodeCount()), compile_ms);
   }
   // TODO(bradnelson): Improve histogram handling of size_t.
   isolate->counters()->wasm_compile_function_peak_memory_bytes()->AddSample(
       static_cast<int>(jsgraph->graph()->zone()->allocation_size()));
   graph_zone_scope.Destroy();
   return code;
 }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8