[llvm] [X86] Combine `uitofp <v x i32> to <v x half>` (PR #121809)

[via llvm-commits]

abhishek-kaushik22 wrote:

With `+f16c` I still see `vmulps	.LCPI0_0(%rip), %ymm1, %ymm1` where 
```
.LCPI0_0:
	.long	0x7f800000                      # float +Inf
	.long	0x7f800000                      # float +Inf
	.long	0x7f800000                      # float +Inf
	.long	0x7f800000                      # float +Inf
	.long	0x7f800000                      # float +Inf
	.long	0x7f800000                      # float +Inf
	.long	0x7f800000                      # float +Inf
	.long	0x7f800000                      # float +Inf
``` 
in the assembly. Thanks @phoebewang for the comments. 

https://github.com/llvm/llvm-project/pull/121809