e711a0c80f
1. Add MipsPat to optimize (andi (srl (truncate i64 $1), x), y) to (andi (truncate (dsrl i64 $1, x)), y). 2. Add MipsPat to optimize (ext (truncate i64 $1), x, y) to (truncate (dext i64 $1, x, y)). The assembly result is the same as gcc. Fixes https://github.com/llvm/llvm-project/issues/42826