[llvm] [BOLT] Support instrumentation hook via DT_FINI_ARRAY (PR #67348)

[Job Noorman via llvm-commits]

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@@ -1276,6 +1280,57 @@ void RewriteInstance::discoverFileObjects() {
   registerFragments();
 }
 
+Error RewriteInstance::discoverFiniAddress() {
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mtvec wrote:

I'd say it's more ELF-specific so `RewriteInstance` would be a better place for it. The logic only deals with somehow overwriting the fini address and, in principle, it doesn't really care about the runtime library. Currently, only the runtime library uses this feature but maybe it could be used by something else as well in the future?

https://github.com/llvm/llvm-project/pull/67348