Remove the debugger_ field from Isolate in a PRODUCT build

runtime/vm/object_test.cc

Index: runtime/vm/object_test.cc
diff --git a/runtime/vm/object_test.cc b/runtime/vm/object_test.cc
index bf4515386ce299bdd4e9cc0e6f74c584796de247..0b84430850c7ac80bd8b8bd026db4d175375cda5 100644
--- a/runtime/vm/object_test.cc
+++ b/runtime/vm/object_test.cc
@@ -3975,10 +3975,9 @@ TEST_CASE(FunctionSourceFingerprint) {
   EXPECT_EQ(a_test6.SourceFingerprint(), b_test6.SourceFingerprint());
 }
 
+#ifndef PRODUCT
+
 TEST_CASE(FunctionWithBreakpointNotInlined) {
-  if (!FLAG_support_debugger) {
-    return;
-  }
   const char* kScriptChars =
       "class A {\n"
       "  a() {\n"
@@ -4043,8 +4042,6 @@ ISOLATE_UNIT_TEST_CASE(SpecialClassesHaveEmptyArrays) {
   EXPECT(array.IsArray());
 }
 
-#ifndef PRODUCT
-
 class ObjectAccumulator : public ObjectVisitor {
  public:
   explicit ObjectAccumulator(GrowableArray<Object*>* objects)