fortran: ICE in gfc_conv_constant_to_tree PR93604

fortran: ICE in gfc_conv_constant_to_tree PR93604

Using a BOZ constant in a structure constructor in a data statement
resulted in an ICE. Output a "BOZ literal constant cannot appear in
a structure constructor" error message instead.

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

Test case added later.

gcc/fortran/ChangeLog

	PR fortran/93604
	* decl.c (gfc_match_data) : Check whether the data expression
	is a derived type and is a constructor. If a BOZ constant
	is encountered in the constructor output an error and return
	MATCH_ERROR.

gcc/testsuite/ChangeLog

	PR fortran/93604
	* gfortran.dg/pr93604.f90 : New test.