[objects.h splitting] Move out Dictionary and related classes.

BUG=v8:5402
R=mstarzinger@chromium.org

Change-Id: Ib53721867e0978b6f4f127883ae1b72145adb6e8
Reviewed-on: https://chromium-review.googlesource.com/461863Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44369}

BUILD.gn

@@ -1700,6 +1700,7 @@ v8_source_set("v8_base") {
     "src/objects.cc",
     "src/objects.h",
     "src/objects/descriptor-array.h",
+    "src/objects/dictionary.h",
     "src/objects/frame-array-inl.h",
     "src/objects/frame-array.h",
     "src/objects/literal-objects.cc",

src/contexts-inl.h

@@ -7,6 +7,7 @@
 
 #include "src/contexts.h"
 #include "src/objects-inl.h"
+#include "src/objects/dictionary.h"
 #include "src/objects/regexp-match-info.h"
 
 namespace v8 {

src/heap/heap.cc

@@ -483,6 +483,9 @@ const char* Heap::GetSpaceName(int idx) {
   return nullptr;
 }
 
+void Heap::SetRootCodeStubs(UnseededNumberDictionary* value) {
+  roots_[kCodeStubsRootIndex] = value;
+}
 
 void Heap::RepairFreeListsAfterDeserialization() {
   PagedSpaces spaces(this);

src/heap/heap.h

@@ -1091,9 +1091,7 @@ class Heap {
   Object** roots_array_start() { return roots_; }
 
   // Sets the stub_cache_ (only used when expanding the dictionary).
-  void SetRootCodeStubs(UnseededNumberDictionary* value) {
-    roots_[kCodeStubsRootIndex] = value;
-  }
+  void SetRootCodeStubs(UnseededNumberDictionary* value);
 
   void SetRootMaterializedObjects(FixedArray* objects) {
     roots_[kMaterializedObjectsRootIndex] = objects;

src/v8.gyp

@@ -1119,6 +1119,7 @@
         'objects.cc',
         'objects.h',
         'objects/descriptor-array.h',
+        'objects/dictionary.h',
         'objects/frame-array.h',
         'objects/frame-array-inl.h',
         'objects/literal-objects.cc',