Remove fields from Isolate in Product mode

tests/standalone/standalone.status

 # Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 # WARNING:
 # Tests using the multitest feature where failure is expected should *also* be
 # listed in tests/lib/analyzer/analyze_tests.status without the "standalone"
 # prefix.
 
 io/raw_socket_test: Pass, RuntimeError # Issue 28288
@@ skipping 247 matching lines @@
 [ $mode == product ]
 no_profiler_test: SkipByDesign
 no_support_coverage_test: SkipByDesign
 no_support_debugger_test: SkipByDesign
 no_support_disassembler_test: SkipByDesign
 no_support_il_printer_test: SkipByDesign
 no_support_service_test: SkipByDesign
 no_support_timeline_test: SkipByDesign
 io/stdio_implicit_close_test: Skip # SkipByDesign
 dart_developer_env_test: SkipByDesign
+verbose_gc_to_bmu_test: SkipByDesign  # No verbose_gc in product mode
 
 # Following tests are skipped on dart_app as package mapping is not supported.
 [ $runtime == dart_precompiled || $compiler == app_jit ]
 package/scenarios/packages_file_strange_formatting/mixed_line_ends_test: Skip
 package/scenarios/packages_file_strange_formatting/empty_lines_test: Skip
 package/scenarios/invalid/invalid_utf8_test: Skip
 package/scenarios/invalid/same_package_twice_test: Skip
 package/scenarios/invalid/non_existent_packages_file_test: Skip
 package/scenarios/empty_packages_file/empty_packages_file_noimports_test: Skip
 package/scenarios/packages_option_only/packages_option_only_noimports_test: Skip
@@ skipping 189 matching lines @@
 package/package_test: Fail # Unable to parse package files Flutter Issue 9115
 #unboxed_int_converter_test: Fail # Unable to parse package files Flutter Issue 9115
 io/process_run_output_test: Fail # Unable to parse package files Flutter Issue 9115
 
 io/dependency_graph_test: CompileTimeError # Imports dart:mirrors
 io/skipping_dart2js_compilations_test: CompileTimeError # Uses mirrors
 io/status_file_parser_test: CompileTimeError # Uses mirrors
 io/test_harness_analyzer_test: CompileTimeError # Uses mirrors
 io/test_runner_test: CompileTimeError # Uses mirrors
 status_expression_test: CompileTimeError # Uses mirrors