[InstCombine] Optimize and of icmps with power-of-2 and contiguous masks

[InstCombine] Optimize and of icmps with power-of-2 and contiguous masks

Add an instance combine optimization for expressions of the form:

(%arg u< C1) & ((%arg & C2) != C2) -> %arg u< C2

Where C1 is a power-of-2 and C2 is a contiguous mask starting 1 bit below
C1. This commit resolves GitHub missed-optimization issue #54856.

Validation of scalar tests:
  - https://alive2.llvm.org/ce/z/JfKjiU
  - https://alive2.llvm.org/ce/z/AruHY_
  - https://alive2.llvm.org/ce/z/JAiR6t
  - https://alive2.llvm.org/ce/z/S2X2e5
  - https://alive2.llvm.org/ce/z/4cycdE
  - https://alive2.llvm.org/ce/z/NcDiLP

Validation of vector tests:
  - https://alive2.llvm.org/ce/z/ABY6tE
  - https://alive2.llvm.org/ce/z/BTJi3s
  - https://alive2.llvm.org/ce/z/3BKWpu
  - https://alive2.llvm.org/ce/z/RrAbkj
  - https://alive2.llvm.org/ce/z/nM6fsN

Reviewed By: goldstein.w.n

Differential Revision: https://reviews.llvm.org/D125717