Add a ResourceConstraint for the embedder to specify that V8 is running on a memory constrained dev…

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index d587b81fd3461202a807bcdd0b68ab7f25f6d5a4..6cfea2a3484157384ad71a7d20f746407b0347d5 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -620,7 +620,8 @@ ResourceConstraints::ResourceConstraints()
   : max_young_space_size_(0),
     max_old_space_size_(0),
     max_executable_size_(0),
-    stack_limit_(NULL) { }
+    stack_limit_(NULL),
+    is_memory_constrained_(false) { }
 
 
 bool SetResourceConstraints(ResourceConstraints* constraints) {
@@ -641,6 +642,7 @@ bool SetResourceConstraints(ResourceConstraints* constraints) {
     uintptr_t limit = reinterpret_cast<uintptr_t>(constraints->stack_limit());
     isolate->stack_guard()->SetStackLimit(limit);
   }
+  isolate->setIsMemoryConstrained(constraints->is_memory_constrained());
   return true;
 }