[crac] RFR: Drop perfdata and cppath [v2]

[Anton Kozlov]

On Mon, 2 Oct 2023 19:51:51 GMT, Radim Vansa <rvansa at openjdk.org> wrote:

>> Storing PerfMemory contents into file might be fragile; if the file is corrupted (e.g. due to wrong permissions) JVM might receive SIGBUS when updating performance counters after restore.
>> This commit provides alternate solution, moving the shared file-mapped memory into private anonymous memory during C/R.
>
> Radim Vansa has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Add jcmd <pid> PerfCounter.print to the test

It should be possible to remove 

static int checkpoint_fd = -1;


from https://github.com/openjdk/crac/pull/119/files#diff-7313eb3d328797a7720fa1b2b73cd159934506593443e45534baad80cb1382b7R66

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PR Review: https://git.openjdk.org/crac/pull/119#pullrequestreview-1674179076