[DAGCombiner] Extend FP-to-Int cast without requiring nsz (#161093)

This patch updates the FP-to-Int conversion handling:
- For signed integers: use `ftrunc` followed by clamping to the target
integer range.
- For unsigned integers: apply `fabs` + `ftrunc`, then clamp.

This removes the previous dependence on `nsz` and ensures correct
lowering for both signed and unsigned cases.

I've tested the code generation of -mtriple=amdgcn. It seems that the
assembly code is expected, but I'm not sure how to write a general
testcase for every target.

Fixes #160623.

0 files changed, 0 insertions, 0 deletions