[llvm] [GlobalIsel] Combine logic of floating point compares (PR #81886)

[Thorsten Schütt via llvm-commits]

tschuett wrote:

I am not interested in feature parity with Instcombine. I am interested in making this combiner more aggressive (up to a point).

Instcombine has for some Opcodes harsher combines than the Dag that are 10 lines of code. I am interested in these 10 lines combines.

https://github.com/llvm/llvm-project/pull/81886