Remove parent_level field of function type parameters.

runtime/vm/stub_code_arm.cc

Index: runtime/vm/stub_code_arm.cc
diff --git a/runtime/vm/stub_code_arm.cc b/runtime/vm/stub_code_arm.cc
index d8cf21cb95914ba70e13edbfaec9469fa3bc2d67..1ab83806be88062609fc493387b8bf038893ca2a 100644
--- a/runtime/vm/stub_code_arm.cc
+++ b/runtime/vm/stub_code_arm.cc
@@ -1789,8 +1789,12 @@ static void GenerateSubtypeNTestCacheStub(Assembler* assembler, int n) {
   // R4: instance type arguments (still null if closure).
   __ SmiTag(R8);
   __ CompareImmediate(R8, Smi::RawValue(kClosureCid));
-  __ ldr(R4, FieldAddress(R0, Closure::instantiator_offset()), EQ);
-  __ ldr(R8, FieldAddress(R0, Closure::function_offset()), EQ);
+  __ b(&loop, NE);
+  __ ldr(R4, FieldAddress(R0, Closure::function_type_arguments_offset()));
+  __ CompareObject(R4, Object::null_object());
+  __ b(&not_found, NE);  // Cache cannot be used for generic closures.
+  __ ldr(R4, FieldAddress(R0, Closure::instantiator_type_arguments_offset()));
+  __ ldr(R8, FieldAddress(R0, Closure::function_offset()));
   // R8: instance class id as Smi or function.
   __ Bind(&loop);
   __ ldr(R9,