RFR: 8330181: Move PcDesc cache from nmethod header

[Vladimir Kozlov]

On Mon, 22 Apr 2024 16:54:40 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

> Currently PcDescCache (32 bytes in 64-bit VM: PcDesc* _pc_descs[4]) is allocated in `nmethod` header.
> 
> Moved PcDescContainer (which includes cache) to C heap similar to ExceptionCache to reduce size of `nmethod` header and to remove WXWrite transition when we update the cache in `PcDescCache::add_pc_desc()`.
> 
> Removed `PcDescSearch` class which was leftover from `CompiledMethod` days.
> 
> Tested tier1-4,stress,xcomp and performance.

Looks like I have to test up to tier8 where [JDK-8316392](https://bugs.openjdk.org/browse/JDK-8316392) failed.

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PR Comment: https://git.openjdk.org/jdk/pull/18895#issuecomment-2071370693