[llvm] [LTO] Fix assertion failure in BlockAddress::get during inlining (PR #176044)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 commented:

Regarding the title/commit message, this should reproduce without LTO? Your test demonstrates it does and I would expect inlining within a single TU to also reproduce the issue.

> If a BlockAddress is requested for this block during this window -- for example, when remapping 'asm goto' operands -- BlockAddress::get previously asserted that 'BB->getParent() != nullptr'.

Given we're performing a single inlining at this point, we know the source and destination functions before we start. Is it possible to tighten the Window and set block parents earlier?

https://github.com/llvm/llvm-project/pull/176044