poly_int: rtx_addr_can_trap_p_1

poly_int: rtx_addr_can_trap_p_1

This patch changes the offset and size arguments of
rtx_addr_can_trap_p_1 from HOST_WIDE_INT to poly_int64.  It also
uses a size of -1 rather than 0 to represent an unknown size and
BLKmode rather than VOIDmode to represent an unknown mode.

2017-12-20  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* rtlanal.c (rtx_addr_can_trap_p_1): Take the offset and size
	as poly_int64s rather than HOST_WIDE_INTs.  Use a size of -1
	rather than 0 to represent an unknown size.  Assert that the size
	is known when the mode isn't BLKmode.
	(may_trap_p_1): Use -1 for unknown sizes.
	(rtx_addr_can_trap_p): Likewise.  Pass BLKmode rather than VOIDmode.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>
From-SVN: r255874