Properly hide hidden versioned symbol in executable

Properly hide hidden versioned symbol in executable

A hidden versioned symbol in executable should be forced local if it is
locally defined, not referenced by shared library and not exported.  We
must do it before _bfd_elf_link_renumber_dynsyms.

bfd/

	* elflink.c (_bfd_elf_fix_symbol_flags): Hide hidden versioned
	symbol in executable.
	(elf_link_output_extsym): Don't change bind from global to
	local when linking executable.

ld/

	* testsuite/ld-elf/indirect.exp: Add a test for PR 18720.
	* testsuite/ld-elf/pr18720.rd: New file.