Hi,
This is a followup patch to PR81388's fix.  According to Richi,
POINTER_TYPE_OVERFLOW_UNDEFINED was added in -fstrict-overflow
warning work.  Given:
  A) strict-overflow was removed;
  B) memory object can not wrap in address space;
  C) existing code doesn't take it in consideration, as in nowrap_type_p.
This patch makes it always true thus removes definition/usage of the macro.
Bootstrap and test on x86_64 and AArch64.  Is it OK?

Thanks,
bin
2017-07-20  Bin Cheng  <bin.cheng@arm.com>

	* tree.h (POINTER_TYPE_OVERFLOW_UNDEFINED): Delete.
	* fold-const.c (fold_comparison, fold_binary_loc): Delete use of
	above macro.
	* match.pd: Ditto in address comparison pattern.

gcc/testsuite/ChangeLog
2017-07-20  Bin Cheng  <bin.cheng@arm.com>

	* gcc.dg/no-strict-overflow-7.c: Revise comment and test string.
	* gcc.dg/tree-ssa/pr81388-1.c: Ditto.