[Fortran] ICE: Invalid expression in gfc_element_size PR93601

[Fortran] ICE: Invalid expression in gfc_element_size PR93601

ICE occurs when assigning a BOZ constant to an class(*) variable
with the allocatable attribute. Use of BOZ constants outside
data statements and int/real/dble/cmplx intrinsics is not allowed.

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

gcc/fortran/ChangeLog

	PR fortran/93601
	* match.c (gfc_match_assignment) : Reject assignment if
	the lhs stype is BT_CLASS and the rhs type is BT_BOZ.

gcc/testsuite/ChangeLog

	PR fortran/93601
	* gfortran.dg/pr93601.f90 : New test.