[InstCombine] complete (X << Z) / (Y << Z) --> X / Y

Add one more situations for this fold.
For unsigned div, 'nsw' on both shifts + 'nuw' on the dividend.

Alive2: https://alive2.llvm.org/ce/z/sELF76

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D139997