[NFC][DAGCombine][X86] Tests for 'A - (A & C)' pattern (PR44448)

Name: PR44448  ptr - (ptr & C) -> ptr & (~C)
%bias = and i32 %ptr, C
%r = sub i32 %ptr, %bias
  =>
%r = and i32 %ptr, ~C

The main motivational pattern involes pointer-typed values,
so this transform can't really be done in middle-end.

See
  https://bugs.llvm.org/show_bug.cgi?id=44448
  https://reviews.llvm.org/D71499