BFD: Exclude sections with no content from compress check.

BFD: Exclude sections with no content from compress check.

The check in bfd_get_full_section_contents is trying to check that we don't
allocate more space for a section than the size of the section is on disk.

Previously we excluded linker created sections since they didn't have a size on
disk.  However we also need to exclude sections with no content as well such as
the BSS section.  Space for these would not have been allocated by the assembler
and so the check would incorrectly fail.

bfd/ChangeLog:

	PR binutils/24753
	* compress.c (bfd_get_full_section_contents): Exclude sections with no
	content.

gas/ChangeLog:

	PR binutils/24753
	* testsuite/gas/arm/pr24753.d: New test.
	* testsuite/gas/arm/pr24753.s: New test.

(cherry picked from commit c36876fe5b5bac1c404ab2ca82bfbfb2ed9a2717)