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

[via cfe-commits]

tangaac wrote:

the original test is from gcc
```cpp
int divw(long a, long b) { 
  return (int)a / (int)b; 
}

unsigned int divwu(long a, long b) { 
  return (unsigned int)a / (unsigned int)b; 
}

int modw(long a, long b) { 
  return (int)a % (int)b; 
}

unsigned int modwu(long a, long b) { 
  return (unsigned int)a % (unsigned int)b; 
}
```

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