Fix PR ld/22727 (TLS breakage in PIC/PIE mode on SPARC).

Fix PR ld/22727 (TLS breakage in PIC/PIE mode on SPARC).

There are actually 2 different bugs:
 1. TLS transition is broken in PIE mode.
 2. TLS is broken in PIC/PIE mode when the __tls_get_addr symbol
    is versioned  (as is the case on Linux and Solaris at least).

The 1st bug is fixed by reverting the problematic change for now
(note that the associated test doesn't pass on SPARC because of another
issue so there is  no formal regression in the testsuite). The 2nd bug
is fixed by changing the  call to _bfd_generic_link_add_one_symbol
on __tls_get_addr into a mere lookup in _bfd_sparc_elf_check_relocs.

bfd/
	* elfxx-sparc.c (_bfd_sparc_elf_check_relocs) <R_SPARC_TLS_GD_CALL>:
	Do a mere lookup of the __tls_get_addr symbol instead of adding it.

	Revert
	2017-10-19  H.J. Lu  <hongjiu.lu@intel.com>

	PR ld/22263
	* elfxx-sparc.c (sparc_elf_tls_transition): Replace
	bfd_link_pic with !bfd_link_executable, !bfd_link_pic with
	bfd_link_executable for TLS check.
	(_bfd_sparc_elf_check_relocs): Likewise.
	(allocate_dynrelocs): Likewise.
	(_bfd_sparc_elf_relocate_section): Likewise.
ld/
	* testsuite/ld-sparc/sparc.exp (32-bit: Helper shared library):
	Link with a version script.
	(32-bit: TLS -fpie): New test.
	(64-bit: Helper shared library): Link with a version script.
	(64-bit: TLS -fpie): New test.
	(64-bit: GOTDATA relocations): Pass -Av9 to the assembler.
	* testsuite/ld-sparc/tlslib.ver: New file.
	* testsuite/ld-sparc/tlspie32.dd: Likewise.
	* testsuite/ld-sparc/tlspie32.s: Likewise.
	* testsuite/ld-sparc/tlspie64.dd: Likewise.
	* testsuite/ld-sparc/tlspie64.s: Likewise.
	* testsuite/ld-sparc/tlssunbin32.dd: Adjust for versioned symbol.
	* testsuite/ld-sparc/tlssunbin32.rd: Likewise.
	* testsuite/ld-sparc/tlssunbin32.sd: Likewise.
	* testsuite/ld-sparc/tlssunbin64.dd: Likewise.
	* testsuite/ld-sparc/tlssunbin64.rd: Likewise.
	* testsuite/ld-sparc/tlssunbin64.sd: Likewise.