[turbofan] Move BytecodeGraphBuilder class out of its header file

All we really need to expose is a single function that builds the graph.
This change drastically simplifies the header file.

Change-Id: If185687b8220bdd253f967be9ab2ea3b088e5423
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1585856Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61068}

src/compiler/js-inlining.cc

@@ -493,11 +493,10 @@ Reduction JSInliner::ReduceJSCall(Node* node) {
       flags |= JSTypeHintLowering::kBailoutOnUninitialized;
     }
     CallFrequency frequency = call.frequency();
-    BytecodeGraphBuilder graph_builder(
+    BuildGraphFromBytecode(
         zone(), bytecode_array, shared_info, feedback_vector, BailoutId::None(),
         jsgraph(), frequency, source_positions_, native_context(), inlining_id,
         flags, false, info_->is_analyze_environment_liveness());
-    graph_builder.CreateGraph();
 
     // Extract the inlinee start/end nodes.
     start = graph()->start();

src/compiler/pipeline.cc

@@ -1066,14 +1066,13 @@ struct GraphBuilderPhase {
       flags |= JSTypeHintLowering::kBailoutOnUninitialized;
     }
     CallFrequency frequency = CallFrequency(1.0f);
-    BytecodeGraphBuilder graph_builder(
+    BuildGraphFromBytecode(
         temp_zone, data->info()->bytecode_array(), data->info()->shared_info(),
         handle(data->info()->closure()->feedback_vector(), data->isolate()),
         data->info()->osr_offset(), data->jsgraph(), frequency,
         data->source_positions(), data->native_context(),
         SourcePosition::kNotInlined, flags, true,
         data->info()->is_analyze_environment_liveness());
-    graph_builder.CreateGraph();
   }
 };