* sysdeps/arm/frame.h (struct layout): Make pointers __unbounded.

	* sysdeps/arm/frame.h (struct layout): Make pointers __unbounded.
	* sysdeps/generic/frame.h: Likewise.
	* sysdeps/generic/backtrace.c (ADVANCE_STACK_FRAME): Wrap bounds
	around return value.
	(__backtrace): Qualify frame-pointer chain and return address
	pointers as __unbounded.  Wrap bounds around variable `current'.
	* sysdeps/generic/segfault.c (ADVANCE_STACK_FRAME): Wrap bounds
	around return value.
	(catch_segfault): Qualify frame-pointer chain and return address
	pointers as __unbounded.  Wrap bounds around variable `current'.
	* sysdeps/i386/backtrace.c (struct layout): Make pointers __unbounded.
	(ADVANCE_STACK_FRAME): Wrap bounds around return value.
	* sysdeps/powerpc/backtrace.c (struct layout): Make pointers __unbounded.
	(__backtrace): Qualify frame-pointer chain and return address
	pointers as __unbounded.  Wrap bounds around variable `current'.