RFR: 8375712: Convert java/lang/runtime tests to use JUnit

[Chen Liang]

On Wed, 21 Jan 2026 19:59:14 GMT, Johannes Döbler <duke at openjdk.org> wrote:

>> This PR converts the tests under `test/jdk/java/lang/runtime/` to use JUnit. Mostly converted by the automatic conversion tool, but there's a manual tweak to use `assertThrows` instead of the current manual `try-catch`. Also one manual fix. The changes are in separate commits, which should help reviewing.
>> 
>> Thanks!
>
> test/jdk/java/lang/runtime/SwitchBootstrapsTest.java line 161:
> 
>> 159:         testEnum(E1.B, 1, 3, "B", "C", "A", E1.class);
>> 160:         assertThrows(IllegalArgumentException.class, () ->
>> 161:             testEnum(E1.B, 0, -1, E2.class)
> 
> for readability it could be worth to add a helper method 
> `testEnumError(Class<? extends RuntimeException> exceptionClass, Enum<?> target, int start, int result, Object... labels)`

The `start` and `result` arguments here are completely unused.

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PR Review Comment: https://git.openjdk.org/jdk/pull/29350#discussion_r2714149186