re PR fortran/13201 (PARAMETER variables of nonconstant shape are accepted)

PR fortran/13201
* resolve.c (resolve_symbol): Verify that the shape of a
parameter array is not only explicit, but also constant.
* array.c (gfc_is_compile_time_shape): New function.
* gfortran.h (gfc_is_compile_time_shape): Add prototype.

From-SVN: r84400