Add methods to enable configuration of ResourceConstraints based on limits derived at runtime.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 0a38fa9f32b2b3e3932a178d756c80b44b1a0c1e..00147c3b3255195ac5e17335c21baa6a8fdfc72d 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -609,10 +609,19 @@ ResourceConstraints::ResourceConstraints()
 bool SetResourceConstraints(ResourceConstraints* constraints) {
   i::Isolate* isolate = EnterIsolateIfNeeded();
 
+  bool changed_memory_constrained = false;
+  if (constraints->is_memory_constrained().has_value &&
+      !i::FLAG_force_memory_constrained.has_value) {
+    isolate->set_is_memory_constrained(
+        constraints->is_memory_constrained().value);
+    changed_memory_constrained = true;
+  }
+
   int young_space_size = constraints->max_young_space_size();
   int old_gen_size = constraints->max_old_space_size();
   int max_executable_size = constraints->max_executable_size();
-  if (young_space_size != 0 || old_gen_size != 0 || max_executable_size != 0) {
+  if (young_space_size != 0 || old_gen_size != 0 || max_executable_size != 0 ||
+      changed_memory_constrained) {
     // After initialization it's too late to change Heap constraints.
     ASSERT(!isolate->IsInitialized());
     bool result = isolate->heap()->ConfigureHeap(young_space_size / 2,
@@ -624,11 +633,6 @@ 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 &&
-      !i::FLAG_force_memory_constrained.has_value) {
-    isolate->set_is_memory_constrained(
-        constraints->is_memory_constrained().value);
-  }
   return true;
 }