Add Genericity enum in VM to distinguish how a type is uninstantiated.

runtime/vm/parser.cc

Index: runtime/vm/parser.cc
diff --git a/runtime/vm/parser.cc b/runtime/vm/parser.cc
index a1b5c73528b189f07185d76fe5aa556489569503..20ab695405b4df8ebd5c0bf1a742b9424a1f3918 100644
--- a/runtime/vm/parser.cc
+++ b/runtime/vm/parser.cc
@@ -12588,16 +12588,10 @@ bool Parser::AreFunctionInstantiatorsRequired() const {
 bool Parser::InGenericFunctionScope() const {
   if (!innermost_function().IsNull()) {
     // With one more free tag bit in Function, we could cache this information.
-    if (innermost_function().IsGeneric()) {
+    if (innermost_function().IsGeneric() ||
+        innermost_function().HasGenericParent()) {
       return true;
     }
-    Function& parent = Function::Handle(innermost_function().parent_function());
-    while (!parent.IsNull()) {
-      if (parent.IsGeneric()) {
-        return true;
-      }
-      parent = parent.parent_function();
-    }
   }
   return false;
 }