Recommit [AArch64] Improve codegen for shifted mask op

The original change compares `APInt` to check the constant is the same or not. But shift amount may have different constant types.
So, this patch change to use `getZExtValue` to compare constant value.

Original comment:
The special case for bit extraction pattern is  `((x >> C) & mask) << C`.
It can be combined to `x & (mask << C)` by return true in isDesirableToCommuteWithShift.

Fix: #56427

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D136014