Clear HAS_RELOC if there are no relocations

Clear HAS_RELOC if there are no relocations

The HAS_RELOC bit should be cleared when relocations are removed from
relocatable files.

bfd/

	PR binutils/19547
	* elf.c (assign_section_numbers): Clear HAS_RELOC if there are
	no relocations in relocatable files.

binutils/

	PR binutils/19547
	* testsuite/binutils-all/objcopy.exp
	(objcopy_test_without_global_symbol): New proc.
	Run objcopy_test_without_global_symbol.
	* testsuite/binutils-all/pr19547.c: New file.