Move objects-visiting into heap.

BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # TODO(jochen): These will need to be user-settable to support standalone V8
 # builds.
 v8_compress_startup_data = "off"
 v8_deprecation_warnings = false
 v8_enable_disassembler = false
 v8_enable_gdbjit = false
@@ skipping 638 matching lines @@
     "src/heap/gc-tracer.cc",
     "src/heap/gc-tracer.h",
     "src/heap/heap-inl.h",
     "src/heap/heap.cc",
     "src/heap/heap.h",
     "src/heap/incremental-marking.cc",
     "src/heap/incremental-marking.h",
     "src/heap/mark-compact-inl.h",
     "src/heap/mark-compact.cc",
     "src/heap/mark-compact.h",
+    "src/heap/objects-visiting-inl.h",
+    "src/heap/objects-visiting.cc",
+    "src/heap/objects-visiting.h",
     "src/heap/spaces-inl.h",
     "src/heap/spaces.cc",
     "src/heap/spaces.h",
     "src/heap/sweeper-thread.h",
     "src/heap/sweeper-thread.cc",
     "src/hydrogen-alias-analysis.h",
     "src/hydrogen-bce.cc",
     "src/hydrogen-bce.h",
     "src/hydrogen-bch.cc",
     "src/hydrogen-bch.h",
@@ skipping 82 matching lines @@
     "src/lookup.cc",
     "src/lookup.h",
     "src/macro-assembler.h",
     "src/messages.cc",
     "src/messages.h",
     "src/msan.h",
     "src/natives.h",
     "src/objects-debug.cc",
     "src/objects-inl.h",
     "src/objects-printer.cc",
-    "src/objects-visiting.cc",
-    "src/objects-visiting.h",
     "src/objects.cc",
     "src/objects.h",
     "src/optimizing-compiler-thread.cc",
     "src/optimizing-compiler-thread.h",
     "src/ostreams.cc",
     "src/ostreams.h",
     "src/parser.cc",
     "src/parser.h",
     "src/perf-jit.cc",
     "src/perf-jit.h",
@@ skipping 512 matching lines @@
     deps = [
       ":v8_base",
       ":v8_nosnapshot",
     ]
   }
 
   direct_dependent_configs = [ ":external_config" ]
 }
 
 }