dwarf: Properly check holes in .debug_ranges/debug_rnglists

dwarf: Properly check holes in .debug_ranges/debug_rnglists

Don't warn if the offset of the first entry in .debug_rnglists starts
right after the header.  Warn holes in .debug_ranges and debug_rnglists
sections only if the last end pointer isn't the same as the current
start pointer.

	PR binutils/32927
	* dwarf.c (display_debug_ranges_list): Return the pointer to the
	end.
	(display_debug_ranges): Don't warn if the offset of the first
	entry in .debug_rnglists starts right after the header.  Warn a
	hole only if the last end pointer is the same as the next pointer.
	* testsuite/binutils-all/x86-64/dwarf4.s: New file.
	* testsuite/binutils-all/x86-64/dwarf5.s: Likewise.
	* testsuite/binutils-all/x86-64/pr32927-1.d: Likewise.
	* testsuite/binutils-all/x86-64/pr32927-2.d: Likewise.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Co-Authored-By: Alan Modra <amodra@gmail.com>