[llvm] Reapply "RuntimeLibcalls: Use get_host_tool_path for executables used … (#159488) (PR #159489)

[Martin Storsjö via llvm-commits]

mstorsjo wrote:

> > I won't be able to look into this more until tomorrow, but this seems to have broken the RISC-V cross-build bots e.g. https://lab.llvm.org/buildbot/#/builders/87/builds/3257
> 
> Attempt to fix #159707

Oh, sorry, I see this seems to try to address this issue!

https://github.com/llvm/llvm-project/pull/159489