Eliminate hardcode_libdir_flag_spec_ld tag variable.

Eliminate hardcode_libdir_flag_spec_ld tag variable.

* libltdl/config/ltmain.m4sh (func_mode_link): Set $wl to empty
if $LD is used for creating shared libraries.  Do not use
hardcode_libdir_flag_spec_ld any more.
* libltdl/m4/libtool.m4 (_LT_LINKER_SHLIBS, _LT_LANG_CXX_CONFIG)
(_LT_LANG_F77_CONFIG, _LT_LANG_FC_CONFIG, _LT_SYS_DYNAMIC_LINKER)
<hardcode_libdir_flag_spec_ld>: Remove all instances of the tag
variable.
(_LT_LINKER_SHLIBS) [linux, xlf] <hardcode_libdir_flag_spec>:
Set variable, including ${wl}.  Fixes hardcoding in programs
created by XL Fortran on GNU/Linux.
* NEWS, THANKS: Update.
Report by Paul H. Hargrove.

Signed-off-by: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>