sparc: check for log double support in gcc

To compile the quad float emulation library gcc needs
__LONG_DOUBLE_128__ macro defined. Check first, if not
supported then revert to the qp_ops.c stubs

Signed-off-by: Konrad Eisele <konrad@gaisler.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

libc/sysdeps/linux/sparc/Makefile.arch

@@ -16,9 +16,15 @@ CSRC += sigaction.c
 SSRC += fork.S vfork.S
 endif
 
+# check weather __LONG_DOUBLE_128__ is defined (long double support)
+UCLIBC_SPARC_HAS_LONG_DOUBLE=$(shell if [ "x`$(CC) -E -dM -xc /dev/null 2>&1 | grep __LONG_DOUBLE_128__`" != "x" ]; then echo "y"; fi)
+ifeq ($(UCLIBC_SPARC_HAS_LONG_DOUBLE),y)
 CSRC += $(foreach f, \
 	q_div.c   q_fle.c    q_mul.c   q_qtoll.c   q_stoq.c    \
 	mp_clz_tab.c  q_dtoq.c  q_flt.c    q_neg.c   q_qtos.c    q_sub.c    \
 	q_add.c      q_feq.c   q_fne.c    q_qtod.c  q_qtou.c    q_ulltoq.c  \
 	q_cmp.c      q_fge.c   q_itoq.c   q_qtoull.c  q_util.c    \
 	q_cmpe.c     q_fgt.c   q_lltoq.c  q_qtoi.c  q_sqrt.c    q_utoq.c, soft-fp/$(f))
+else
+CSRC += qp_ops.c
+endif