Support unwind information in PerfJITEventListener

[vchuravy]

External profilers might want to do DWARF based unwinding if the JIT code was built with frame-pointer-optimization.

This was introduced in 2016 for V8 https://groups.google.com/g/linux.kernel/c/sq5WbV7xaec?pli=1 and so far LLVM politely ignores it

llvm-project/llvm/lib/ExecutionEngine/PerfJITEvents/PerfJITEventListener.cpp

Line 113 in ee9a0f3

JIT_CODE_UNWINDING_INFO = 4, // not emitted

I won't have time to work on this, but wanted to leave some breadcrumbs around why we disabled FPO in Julia JuliaLang/julia#48660

[llvmbot]

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[llvmbot]

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