Support objcopy --remove-section=.relaFOO
* objcopy.c (handle_remove_section_option): Don't require a dot
after .rela and .rel to handle a possible relocation section.
* testsuite/binutils-all/remove-relocs-07.s,
* testsuite/binutils-all/remove-relocs-07.d,
* testsuite/binutils-all/remove-relocs-08.d: New tests.
* testsuite/binutils-all/remove-relocs-01.d,
* testsuite/binutils-all/remove-relocs-04.d,
* testsuite/binutils-all/remove-relocs-05.d,
* testsuite/binutils-all/remove-relocs-06.d: Exclude mips64-openbsd.