Remove (Unused).

testsuites/aclocal/gcc-isystem.m4

@@ -1,25 +0,0 @@
-dnl
-dnl $Id$
-dnl
-dnl Check whether the gcc accepts -isystem
-dnl
-
-AC_DEFUN([RTEMS_GCC_ISYSTEM],
-[AC_REQUIRE([RTEMS_PROG_CC])
-AC_CACHE_CHECK(whether $CC accepts -isystem,rtems_cv_gcc_isystem,
-[
-rtems_cv_gcc_isystem=no
-if test x"$GCC" = x"yes"; then
-cat << EOF > conftest.h
-int conftest123();
-EOF
-cat << EOF > conftest.c
-#include <conftest.h>
-int conftest123() {}
-EOF
-  if test -z "`${CC} -isystem./ -c conftest.c 2>&1`";then
-    rtems_cv_gcc_isystem=yes
-  fi
-fi
-rm -f conftest*
-])])