RFR: 8338888: SystemDictionary::class_name_symbol has incorrect length check

[Thomas Stuefe]

On Mon, 26 Aug 2024 02:49:42 GMT, David Holmes <dholmes at openjdk.org> wrote:

> The name length check was incorrectly truncating the length to an int, which is wrong if the name is > `INT_MAX`. Added a test for this case to the existing test cases and fixed an issue with the call to `Exceptions::fthrow` that can hit the `INT_MAX` limitations of `os::vsnprintf` (this is the first in a serious of fixes that will mainly be done under [JDK-8328882](https://bugs.openjdk.org/browse/JDK-8328882) or subtasks thereof).
> 
> Testing:
>  - updated test
>  - tiers 1-3 (sanity)
> 
> Thanks

test/hotspot/jtreg/runtime/exceptionMsgs/NoClassDefFoundError/libNoClassDefFoundErrorTest.c line 53:

> 51:     char* c_name = malloc(len * sizeof(char));
> 52:     if (c_name != NULL) {
> 53:         memset(c_name, 0x59595959, len - 1); // YYYY...

nit, `59` should be enough

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PR Review Comment: https://git.openjdk.org/jdk/pull/20709#discussion_r1732166219