[llvm] RuntimeLibcalls: Describe register-returning divmod libcall ABIs (PR #217825)

[Martin Storsjö via llvm-commits]

mstorsjo wrote:

> This looks fine to me on the Arm ABI front (based on https://github.com/ARM-software/abi-aa/blob/main/rtabi32/rtabi32.rst#531integer-3232--32-division-functions).
> 
> Will need someone to confirm the Windows side.

I have tested building and running my set of smoke tests for Windows, which do include 32 bit ARM, including cases with divisions, with this branch, without any problems.

https://github.com/llvm/llvm-project/pull/217825