tree-optimization/104466 - fix cut&paste error perventing alias disambiguation

tree-optimization/104466 - fix cut&paste error perventing alias disambiguation

The following fixes a cut&paste error in disambiguating using restrict
info.  Instead of using the for this purpose computed rbase1/rbase2
which preserve MEM_REF bases even when they are based on a decl the
code performs the check on the bases that drop info for those ...

2022-02-10  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/104466
	* tree-ssa-alias.cc (refs_may_alias_p_2): Use rbase1/rbase2
	for the MR_DEPENDENCE checks as intended.

	* gfortran.dg/pr104466.f90: New testcase.