[llvm] [aarch64][win] Add support for import call optimization (equivalent to MSVC /d2ImportCallOptimization) (PR #121516)

[Eli Friedman via llvm-commits]

efriedma-quic wrote:

> it needs to be able to go back and rewrite already-streamed sections

Yes, a relocation (at the assembler level, not in the resulting object).  We have infrastructure to do this if you wanted to.

https://github.com/llvm/llvm-project/pull/121516