[Bug rtl-optimization/108757] We do not simplify (a - (N*M)) / N + M -> a / N

[chip.kerchner at ibm dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108757

--- Comment #15 from Chip Kerchner <chip.kerchner at ibm dot com> ---
How about this (from Peter's testcase)?  Does it still have issues?  It
produces the same assembly.

#define N 32
#define M 2

unsigned long int
foo (unsigned long int a)
{
  return (a - (N*M)) / N + M;
}