[Fortran] ICE in gfc_typenode_for_spec PR93603

[Fortran] ICE in gfc_typenode_for_spec PR93603

Associating a symbol with a BOZ constant caused an ICE.  Output
an error message as an association target cannot be a BOZ
constant.

Original patch provided by Steven G. Kargl  <kargl@gcc.gnu.org>.

gcc/fortran/ChangeLog

	PR fortran/93603
	* match.c (gfc_match_associate) : If target expression
	has the type BT_BOZ output an error and goto
	assocListError.

gcc/testsuite/ChangeLog

	PR fortran/93603
	* gfortran.dg/pr93603.f90 : New test.