Add HOSTING_SLIBS and use it for -pie

ld/

	PR ld/16259
	* Makefile.am (HOSTING_SLIBS): New.
	* configure.host (HOSTING_SLIBS): New.  Used for PIE.
	* configure.in (HOSTING_SLIBS): New AC_SUBST.
	* Makefile.in: Regenerated.
	* configure: Likewise.

ld/testsuite/

	PR ld/16259
	* config/default.exp (get_target_emul): Also set HOSTING_SLIBS.
	* lib/ld-lib.exp (default_ld_link): Use HOSTING_SLIBS for -pie.
Fix a typo