Properly place the NULL STT_FILE symbol

Properly place the NULL STT_FILE symbol

We output a NULL STT_FILE symbol for forced local symbols so that they
are not associated with the STT_FILE symbol for real local symbols. This
patch makes sure that the NULL STT_FILE symbol is placed before forced
local symbols.

bfd/

	PR ld/17975
	* elflink.c (elf_link_output_extsym): Only check filesym_count
	when outputting a NULL FILE symbol.  Set second_pass_sym to
	h->forced_local && !h->root.linker_def.

ld/testsuite/

	PR ld/17975
	* ld-i386/tlsbin-nacl.rd: Likewise.
	* ld-i386/tlsbin.rd: Likewise.
	* ld-i386/tlsbindesc-nacl.rd: Likewise.
	* ld-i386/tlsbindesc.rd: Likewise.
	* ld-i386/tlsdesc-nacl.rd: Likewise.
	* ld-i386/tlsdesc.rd: Likewise.
	* ld-i386/tlsnopic-nacl.rd: Likewise.
	* ld-i386/tlsnopic.rd: Likewise.
	* ld-i386/tlspic-nacl.rd: Likewise.
	* ld-i386/tlspic.rd: Likewise.
	* ld-x86-64/tlsbin-nacl.rd: Likewise.
	* ld-x86-64/tlsbin.rd: Likewise.
	* ld-x86-64/tlsbindesc-nacl.rd: Likewise.
	* ld-x86-64/tlsbindesc.rd: Likewise.
	* ld-x86-64/tlsdesc-nacl.rd: Likewise.
	* ld-x86-64/tlsdesc.rd: Likewise.
	* ld-x86-64/tlspic-nacl.rd: Likewise.
	* ld-x86-64/tlspic.rd: Likewise.