Add testcase for PR 25662 invalid sh_offset for section

Add testcase for PR 25662 invalid sh_offset for section

binutils/ChangeLog:

2020-03-27  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

	PR binutils/25662
	* testsuite/binutils-all/objcopy.exp (objcopy_test): Add argument to
	specify whether an object file or executable should be built and tested.
	Change test names to report whether an object file or executable is
	being tested.
	* testsuite/binutils-all/pr25662.ld: New test.
	* testsuite/binutils-all/pr25662.s: New test.