Ensure IsolateGroup.runSync works in interpreter/bytecode mode.

[aam]

Currently ffi/run_isolate_group_run_test fails on all dyn bots

https://dart-ci.appspot.com/log/any/vm-dyn-linux-debug-x64/224/ffi/run_isolate_group_run_test/0

--- Command "vm" (took 04.000268s):
DART_CONFIGURATION=DebugX64 out/DebugX64/dart --experimental-shared-data -Dtest_runner.configuration=vm-dyn-linux-debug-x64 --interpreter --ignore-unrecognized-flags --packages=/b/s/w/ir/.dart_tool/package_config.json /b/s/w/ir/tests/ffi/run_isolate_group_run_test.dart

exit code:
255

stderr:
Unhandled exception:
Invalid argument(s): Only final and 'vm:shared' variables can be captured by isolate group callbacks.
#0      IsolateGroup._runSync (dart:_internal-patch/internal_patch.dart)
#1      IsolateGroup.runSync (dart:_internal:1162:43)
#2      main (file:///b/s/w/ir/tests/ffi/run_isolate_group_run_test.dart:86:16)
#3      _delayEntrypointInvocation.<anonymous closure> (dart:isolate-patch/isolate_patch.dart:312:33)
#4      _RawReceivePort._handleMessage (dart:isolate-patch/isolate_patch.dart:193:12)

--- Re-run this test:
python3 tools/test