[gardening] Mark vm/dart{,_2}/regress47472_test as slow

The test throws 1 million exceptions which can, especially in debug mode
can take very long.

This addresses flaky timeouts of this test in debug mode.

TEST=ci

Change-Id: Ibfa9108d49303d62aa4267c07e03499d0a831292
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/240700
Reviewed-by: Daco Harkes <[email protected]>
Commit-Queue: Martin Kustermann <[email protected]>

Author: mkustermann

runtime/tests/vm/vm.status

@@ -142,13 +142,15 @@ dart/b162922506_test: SkipSlow # Generates very large input file
 dart/hash_map_probes_limit_test: SkipSlow # Test includes large program compilation.
 dart/minimal_kernel_test: SkipSlow # gen_kernel is too slow in debug mode
 dart/null_safety_autodetection_in_kernel_compiler_test: SkipSlow # gen_kernel is too slow in debug mode
+dart/regress47472_test: Pass, Slow # Slow due to throwing 1 million exceptions.
 dart/spawn_shutdown_test: Pass, Slow # VM Shutdown test, It can take some time for all the isolates to shutdown in a Debug build.
 dart/type_casts_with_null_safety_autodetection_test: Pass, Slow # Very slow in debug mode, uses --optimization-counter-threshold=10
 dart_2/appjit_cha_deopt_test: Pass, Slow # Quite slow in debug mode, uses --optimization-counter-threshold=100
 dart_2/b162922506_test: SkipSlow # Generates very large input file
 dart_2/hash_map_probes_limit_test: SkipSlow # Test includes large program compilation.
 dart_2/minimal_kernel_test: SkipSlow # gen_kernel is too slow in debug mode
 dart_2/null_safety_autodetection_in_kernel_compiler_test: SkipSlow # gen_kernel is too slow in debug mode
+dart_2/regress47472_test: Pass, Slow # Slow due to throwing 1 million exceptions.
 dart_2/spawn_shutdown_test: Pass, Slow # VM Shutdown test, It can take some time for all the isolates to shutdown in a Debug build.
 
 [ $mode == product ]