Fixes a problem with the BFD library running out of memory because it mistakenly

Fixes a problem with the BFD library running out of memory because it mistakenly
thought that an uncompressed .debug_str section was compressed.

	* compress.c (bfd_is_section_compressed): When checking the
	.debug_str section, also check the fifth byte in the section is
	not part of a string.

	* binutils-all/debug_str.s: New test.
	* binutils-all/debug_str.d: New test control file.
	* binutils-all/compress.exp: Run debug_str test.