When using %qs instead of '%s' or %<=%> instead of '=' looks nicer
by having nicer quotes and bold text, if the terminal supports it;
otherwise, plain quotes are used.
gcc/fortran/ChangeLog:
* match.cc (gfc_match_member_sep): Use %<...%> in gfc_error.
* openmp.cc (gfc_match_oacc_routine, gfc_match_omp_context_selector,
gfc_match_omp_context_selector_specification,
gfc_match_omp_declare_variant, resolve_omp_clauses): Likewise;
use %qs instead of '%s'.
* primary.cc (match_real_constant, gfc_match_varspec): Likewise.
* resolve.cc (gfc_resolve_formal_arglist, resolve_operator,
resolve_ordinary_assign): Likewise.