[clang] [llvm] [LoongArch] Support LA V1.1 feature that div.w[u] and mod.w[u] instructions with inputs not signed-extended. (PR #116764)

[Lu Weining via cfe-commits]

SixWeining wrote:

The expectation is at least for this test:
```
define i32 @test(i32 %a, i32 %b) {
  %c = udiv i32 %a, %b
  ret i32 %c
}
```

### without this feature
```
        addi.w  $a1, $a1, 0
        addi.w  $a0, $a0, 0
        div.wu  $a0, $a0, $a1
        ret
```

### with this feature
```
        div.wu  $a0, $a0, $a1
        ret
```

https://github.com/llvm/llvm-project/pull/116764