PR fortran/95881 - ICE in resolve_symbol, at fortran/resolve.c:15175

Avoid NULL pointer dereference.

gcc/fortran/
	PR fortran/95881
	* resolve.c (resolve_symbol): Avoid NULL pointer dereference.

(cherry picked from commit 3cbc0fb39c84ae0a51a9a88649dccd105bf17d6e)

gcc/fortran/resolve.c

@@ -15173,6 +15173,7 @@ resolve_symbol (gfc_symbol *sym)
   if (flag_coarray == GFC_FCOARRAY_LIB && sym->ts.type == BT_CLASS
       && sym->ts.u.derived && CLASS_DATA (sym)
       && CLASS_DATA (sym)->attr.codimension
+      && CLASS_DATA (sym)->ts.u.derived
       && (CLASS_DATA (sym)->ts.u.derived->attr.alloc_comp
 	  || CLASS_DATA (sym)->ts.u.derived->attr.pointer_comp))
     {

gcc/testsuite/gfortran.dg/pr95881.f90

+! { dg-do compile }
+! { dg-options "-fcoarray=lib" }
+! PR fortran/95881 - ICE in resolve_symbol, at fortran/resolve.c:15175
+
+program p
+  type t
+     real, allocatable :: a[:]
+  end type t
+  class(t) :: x     ! { dg-error "must be dummy, allocatable or pointer" }
+  allocate (x%a[*])
+end