[llvm] [RISCV][GISel] Use libcalls for rint, nearbyint, trunc, and round intrinsics. (PR #108779)

[Thorsten Schütt via llvm-commits]

tschuett wrote:

I cannot say much, but the title slightly differs from what you actually legalize, but so what. 4 vs. 5 and some missing fs.

https://github.com/llvm/llvm-project/pull/108779