Simplify temacs build rule.

Simplify temacs build rule.

* configure.in (NS_IMPL_GNUSTEP_TEMACS_LDFLAGS): New output variable.
(START_FILES): Set to empty if NS_IMPL_GNUSTEP.
(GNUSTEP_SYSTEM_HEADERS, GNUSTEP_SYSTEM_LIBRARIES): Do not output,
nothing uses.

* configure: Regenerate.

* src/Makefile.in (GNUSTEP_SYSTEM_LIBRARIES): Remove, unused.
(NS_IMPL_GNUSTEP_TEMACS_LDFLAGS): New, set by configure.
(LD) [NS_IMPL_GNUSTEP]: Set to $(CC) -rdynamic.
(temacs${EXEEXT}): Remove $LOCALCPP, never defined or referenced.
Make most of the NS_IMPL_GNUSTEP case the same as the default case.

* msdos/sed1v2.inp (GNUSTEP_SYSTEM_LIBRARIES): Remove.
(NS_IMPL_GNUSTEP_TEMACS_LDFLAGS): Edit to empty.