[GlobalISel] add missing libcalls and 128-bit support for floating points

Add libcall support for G_FMINNUM, G_FMAXNUM, G_FSQRT, G_FRINT, G_FNEARBYINT.
Add 128-bit libcall support for all simple libcalls.

Reviewers: arsenm, Petar.Avramovic, dsanders, petarj, paquette

Subscribers: wdng, rovka, hiraditya, volkan, llvm-commits

Differential Revision: https://reviews.llvm.org/D75516