[0.6] LLVM intrinsics are looked up in the wrong place

[Keno]

See e.g. https://ci.appveyor.com/project/Keno/pyjulia/build/1.0.15/job/mtc9w4vf23l0nu5y. When llvm lowers intrinsics to libcalls, it apparently tries looking them up in the base executable, which doesn't have them. We should either do look them up in openlibm or, even better, do something like #18927.

[vtjnash]

It should have them? We statically link libopenlibm into most places to make sure this works.

[vchuravy]

Since #18927 is uncertain #16066 might be the more actionable approach.

[KristofferC]

@Keno, anything left to do here?

[Keno]

There is a more generalized problem about communicating with LLVM about libcalls, but I think this particular issue is resolved. A new issue can be filed with a reproducer when this issue rears its head again.