[committed] fortran: Fix ICE on pr96024.f90 on big-endian hosts [PR96024]

[Jakub Jelinek <jakub@redhat.com>]

Hi!

The pr96024.f90 testcase ICEs on big-endian hosts.  The problem is
that length->val.integer is accessed after checking
length->expr_type == EXPR_CONSTANT, but it is a CHARACTER constant
which uses length->val.character union member instead and on big-endian
we end up reading constant 0x100000000 rather than some small number
on little-endian and if target doesn't have enough memory for 4 times
that (i.e. 16GB allocation), it ICEs.

Fixed thusly, bootstrapped/regtested on
{x86_64,i686,powerpc64le,aarch64,s390x}-linux, preapproved in bugzilla
by Harald, committed to trunk and 13, 12, 11 and 10 release branches.

2023-06-09  Jakub Jelinek  <jakub@redhat.com>

	PR fortran/96024
	* primary.cc (gfc_convert_to_structure_constructor): Only do
	constant string ctor length verification and truncation/padding
	if constant length has INTEGER type.

--- gcc/fortran/primary.cc.jj	2023-05-20 15:31:09.183661713 +0200
+++ gcc/fortran/primary.cc	2023-06-08 11:49:39.354875373 +0200
@@ -3188,10 +3188,11 @@ gfc_convert_to_structure_constructor (gf
 	goto cleanup;
 
       /* For a constant string constructor, make sure the length is
-	 correct; truncate of fill with blanks if needed.  */
+	 correct; truncate or fill with blanks if needed.  */
       if (this_comp->ts.type == BT_CHARACTER && !this_comp->attr.allocatable
 	  && this_comp->ts.u.cl && this_comp->ts.u.cl->length
 	  && this_comp->ts.u.cl->length->expr_type == EXPR_CONSTANT
+	  && this_comp->ts.u.cl->length->ts.type == BT_INTEGER
 	  && actual->expr->ts.type == BT_CHARACTER
 	  && actual->expr->expr_type == EXPR_CONSTANT)
 	{

	Jakub