PR fortran/18833
PR fortran/20850
* primary.c (match_varspec): If equiv_flag, don't look at sym's
attributes, call gfc_match_array_ref up to twice and don't do any
substring or component processing.
* resolve.c (resolve_equivalence): Transform REF_ARRAY into
REF_SUBSTRING or nothing if needed. Check that substrings
don't have zero length.
* gfortran.dg/equiv_1.f90: New test.
* gfortran.dg/equiv_2.f90: New test.
* gfortran.fortran-torture/execute/equiv_2.f90: New test.
* gfortran.fortran-torture/execute/equiv_3.f90: New test.
* gfortran.fortran-torture/execute/equiv_4.f90: New test.
From-SVN: r102801
