expand: Fix up expand_doubleword_mod on 32-bit targets [PR98229]

expand: Fix up expand_doubleword_mod on 32-bit targets [PR98229]

As the testcase shows, for 32-bit word size we can end up with op1
up to 0xffffffff (0x100000000 % 0xffffffff == 1 and so we use bit == 32
for that), but the CONST_INT we got from caller is for DImode in that case
and not valid for SImode operations.

The following patch canonicalizes the two spots where the constant needs
canonicalization.

2020-12-10  Jakub Jelinek  <jakub@redhat.com>

	PR rtl-optimization/98229
	* optabs.c (expand_doubleword_mod): Canonicalize op1 and
	1 - INTVAL (op1) as word_mode constants when used in
	word_mode arithmetics.

	* gcc.c-torture/compile/pr98229.c: New test.