Queued methods not reset during code cache flush

[JamesKingdon]

Tested with 17.0.12.1 on Power linux, but problem is likely common to all versions and platforms.

When running in FSD mode class redefinition causes all methods to be unloaded from the code cache. However the existing code fails to reset the extra field for methods that have been queued but not yet compiled. This means that the queued methods can never be compiled during the remainder of the run and this can cause a significant performance penalty. For example,

Before #20628:

Threads     Throughput
    1         3653
    2         7501
    3        11334
    4        16511

After #20628:

Threads     Throughput
    1         6702
    2        14574
    3        21913
    4        29225

I have created #20628 for this problem.

[github-actions]

Issue Number: 20629
Status: Open
Recommended Components: comp:vm, comp:test, comp:build