More fixes for invalid memory accesses triggered by corrupt binaries.

More fixes for invalid memory accesses triggered by corrupt binaries.

	PR binutils/17512
	* dwarf.c (get_encoded_value): Add an 'end' parameter.  Change the
	'data' parameter to a double pointer and return the updated value.
	(decode_location_expression): Update call to get_encoded_value.
	(frame_need_space): Handle the case where one or both of the
	mallocs fails.
	(read_cie): Initialise the cie pointer, even if the read fails.
	(display_debug_frames): Warn if the calculated block_end is before
	the start of the block.  Break the loop if the CIE could not be
	read.  Update call to get_encoded_value.  Warn if the read CFA
	expressions are too big.

	* ieee.c (ieee_archive_p) Skip processing if no bytes are read at
	all.
	(ieee_object_p): Likewise.