[InstCombine] Handle a bitreverse idiom which ends with a bswap (#77677)

This patch handles the following `bitreverse` idiom, which is found in
https://github.com/abseil/abseil-cpp/blob/8bd6445acc4bd0d123da2a44448b7218dfc70939/absl/crc/internal/crc.cc#L75-L80:

```
uint32_t ReverseBits(uint32_t bits) {
  bits = (bits & 0xaaaaaaaau) >> 1 | (bits & 0x55555555u) << 1;
  bits = (bits & 0xccccccccu) >> 2 | (bits & 0x33333333u) << 2;
  bits = (bits & 0xf0f0f0f0u) >> 4 | (bits & 0x0f0f0f0fu) << 4;
  return absl::gbswap_32(bits);
}
```

Alive2: https://alive2.llvm.org/ce/z/ZYXNmj