[wasm] Allow --turbo-stats to collect wasm compilation info.

Enable compilation stats for Wasm code.
As parallel compilation can interfere with these measurements,
also force single threaded compilation when collecting stats.

BUG=None
TEST=None
LOG=N
R=mtrofin@chromium.org

Review-Url: https://codereview.chromium.org/2769743002
Cr-Commit-Position: refs/heads/master@{#44046}

src/compiler/pipeline.cc

@@ -115,6 +115,7 @@ class PipelineData {
 
   // For WASM compile entry point.
   PipelineData(ZoneStats* zone_stats, CompilationInfo* info, JSGraph* jsgraph,
+               PipelineStatistics* pipeline_statistics,
                SourcePositionTable* source_positions,
                ZoneVector<trap_handler::ProtectedInstructionData>*
                    protected_instructions)
@@ -122,6 +123,7 @@ class PipelineData {
         info_(info),
         debug_name_(info_->GetDebugName()),
         zone_stats_(zone_stats),
+        pipeline_statistics_(pipeline_statistics),
         graph_zone_scope_(zone_stats_, ZONE_NAME),
         graph_(jsgraph->graph()),
         source_positions_(source_positions),
@@ -648,7 +650,9 @@ class PipelineWasmCompilationJob final : public CompilationJob {
       : CompilationJob(info->isolate(), info, "TurboFan",
                        State::kReadyToExecute),
         zone_stats_(info->isolate()->allocator()),
-        data_(&zone_stats_, info, jsgraph, source_positions, protected_insts),
+        pipeline_statistics_(CreatePipelineStatistics(info, &zone_stats_)),
+        data_(&zone_stats_, info, jsgraph, pipeline_statistics_.get(),
+              source_positions, protected_insts),
         pipeline_(&data_),
         linkage_(descriptor),
         allow_signalling_nan_(allow_signalling_nan) {}
@@ -660,6 +664,7 @@ class PipelineWasmCompilationJob final : public CompilationJob {
 
  private:
   ZoneStats zone_stats_;
+  std::unique_ptr<PipelineStatistics> pipeline_statistics_;
   PipelineData data_;
   PipelineImpl pipeline_;
   Linkage linkage_;

src/flag-definitions.h

@@ -528,6 +528,8 @@ DEFINE_BOOL(wasm_disable_structured_cloning, false,
             "disable WASM structured cloning")
 DEFINE_INT(wasm_num_compilation_tasks, 10,
            "number of parallel compilation tasks for wasm")
+// Parallel compilation confuses turbo_stats, force single threaded.
+DEFINE_VALUE_IMPLICATION(turbo_stats, wasm_num_compilation_tasks, 0)
 DEFINE_UINT(wasm_max_mem_pages, v8::internal::wasm::kV8MaxWasmMemoryPages,
             "maximum memory size of a wasm instance")
 DEFINE_UINT(wasm_max_table_size, v8::internal::wasm::kV8MaxWasmTableSize,