[llvm] [RegisterCoalescer] Fix SUBREG_TO_REG handling in the RegisterCoalescer. (PR #96839)

[Stefan Pintilie via llvm-commits]

stefanp-ibm wrote:

> > %2 [32r,112r:0) 0 at 32r  L000000000000000F [16r,112r:0) 0 at 16r  weight:0.000000e+00
> 
> Is it typo? The main liverange should not be shorter than subrange. I tried this patch, looks it should be Before coalescing

Yes, this is a typo and I will fix the description. As you mentioned the result should be:
```
%2 [16r,112r:0) 0 at 16r  L000000000000000F [16r,112r:0) 0 at 16r  weight:0.000000e+00
```


https://github.com/llvm/llvm-project/pull/96839