[turbofan] Initial support for monomorphic/polymorphic property loads.

src/compilation-dependencies.cc

Index: src/compilation-dependencies.cc
diff --git a/src/compilation-dependencies.cc b/src/compilation-dependencies.cc
index 643b88ab0ec0875dd32c3f3dd414811862c3a492..2d48153db03458d2adf40c26ca64cafc8889600c 100644
--- a/src/compilation-dependencies.cc
+++ b/src/compilation-dependencies.cc
@@ -106,6 +106,15 @@ void CompilationDependencies::Rollback() {
 }
 
 
+void CompilationDependencies::AssumeMapStable(Handle<Map> map) {
+  DCHECK(map->is_stable());
+  // Do nothing if the map cannot transition.
+  if (map->CanTransition()) {
+    Insert(DependentCode::kPrototypeCheckGroup, map);
+  }
+}
+
+
 void CompilationDependencies::AssumeTransitionStable(
     Handle<AllocationSite> site) {
   // Do nothing if the object doesn't have any useful element transitions left.