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 1bc80d27d1d7761ad7b010a5749ffa804592b519..7c145585986205969eb073bd1c895675f5012529 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -624,7 +624,8 @@ 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_() { }
 
 
 bool SetResourceConstraints(ResourceConstraints* constraints) {
@@ -645,6 +646,10 @@ bool SetResourceConstraints(ResourceConstraints* constraints) {
     uintptr_t limit = reinterpret_cast<uintptr_t>(constraints->stack_limit());
     isolate->stack_guard()->SetStackLimit(limit);
   }
+  if (constraints->is_memory_constrained().has_value) {
+    isolate->set_is_memory_constrained(
+        constraints->is_memory_constrained().value);
+  }
   return true;
 }