Provide baseline for new GC infrastructure.

src/spaces.h

Index: src/spaces.h
diff --git a/src/spaces.h b/src/spaces.h
index a1f0c6b01155e40d82b44389cd859fafbb3b7ea9..c8d5f0c2d334e7f55b73b45dc495240d58a71d79 100644
--- a/src/spaces.h
+++ b/src/spaces.h
@@ -2063,7 +2063,9 @@ class MapSpace : public FixedSpace {
   MapSpace(intptr_t max_capacity, int max_map_space_pages, AllocationSpace id)
       : FixedSpace(max_capacity, id, Map::kSize, "map"),
         max_map_space_pages_(max_map_space_pages) {
-    ASSERT(max_map_space_pages < kMaxMapPageIndex);
+    if (!FLAG_new_gc) {
+      ASSERT(max_map_space_pages < kMaxMapPageIndex);
+    }
   }
 
   // Prepares for a mark-compact GC.
@@ -2076,6 +2078,8 @@ class MapSpace : public FixedSpace {
 
   // Are map pointers encodable into map word?
   bool MapPointersEncodable() {
+    if (FLAG_new_gc) return false;
+
     if (!FLAG_use_big_map_space) {
       ASSERT(CountPagesToTop() <= kMaxMapPageIndex);
       return true;