[JSC] Clean up StructureID related data
Created attachment 458861 [details] Patch
Pull request: https://github.com/WebKit/WebKit/pull/520
Committed r293847 (250318@main): <https://commits.webkit.org/250318@main> Reviewed commits have been landed. Closing PR #520 and removing active labels.
<rdar://problem/92809626>