[llvm] [LiveIntervals] repairIntervalsInRange: recompute width changes (PR #78564)

[Jay Foad via llvm-commits]

https://github.com/jayfoad commented:

I think splitting copies sometimes produces instructions like this, where the def is narrow but there is also an implicit-def of the full width register:
```
$vgpr0 = V_MOV_B32_e32 $sgpr0, implicit $exec, implicit-def $vgpr0_vgpr1, implicit $sgpr0_sgpr1
```
How should these be handled? Your patch will call removeInterval on them.

https://github.com/llvm/llvm-project/pull/78564