Fix some fallout for small targets.

Fix some fallout for small targets.

	PR testsuite/52641
	* gcc.dg/torture/pr86034.c: Use 32-bit base type for a bitfield of
	width > 16 bits.
	* gcc.dg/torture/pr90972.c [avr]: Add option "-w".
	* gcc.dg/torture/pr87693.c: Same.
	* gcc.dg/torture/pr91178.c: Add dg-require-effective-target size32plus.
	* gcc.dg/torture/pr91178-2.c: Same.
	* gcc.dg/torture/20181024-1.c
	* gcc.dg/torture/pr86554-1.c: Use 32-bit integers.
	* gcc.dg/tree-ssa/pr91091-1.c: Same.

From-SVN: r277236