[llvm] [AggressiveInstCombine] Use DL.fitsInLegalInteger instead of TTI.isTypeLegal in consecutive load/store combine. (PR #220310)

[Kewen Meng via llvm-commits]

Kewen12 wrote:

Hi, this PR seems to break bots. Could you please fix it? Thanks!
```
Failed Tests (2):
  LLVM :: Transforms/AggressiveInstCombine/RISCV/or-load.ll
  LLVM :: Transforms/AggressiveInstCombine/RISCV/store-merge.ll
```

https://github.com/llvm/llvm-project/pull/220310