bsd.lib.mk: only ctfmerge if objfiles have a CTF section

PR:		299013
Reported by:	[email protected]
Reviewed by:	emaste
Fixes:		222210c6a8 ("libgcc_s: add libgcc_s_asneeded.so wrapper for gcc 16")
MFC after:	3 days
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D60252

share/mk/bsd.lib.mk

@@ -291,7 +291,7 @@ ${SHLIB_NAME_FULL}: ${SOBJS}
 .endif
 	${_LD:N${CCACHE_BIN}} ${LDFLAGS} ${SSP_CFLAGS} ${SOLINKOPTS} \
 	    -o ${.TARGET} -Wl,-soname,${SONAME} ${SOBJS} ${LDADD}
-.if ${MK_CTF} != "no"
+.if ${MK_CTF} != "no" && defined(SOBJS) && !empty(SOBJS)
 	${CTFMERGE} ${CTFFLAGS} -o ${.TARGET} ${SOBJS}
 .endif
 

share/mk/sys.mk

@@ -165,7 +165,7 @@ CPP		?=	cpp
 CTFFLAGS	?=	-L VERSION
 
 CTFCONVERT	?=	ctfconvert
-CTFMERGE	?=	ctfmerge
+CTFMERGE	?=	ctfmerge -t
 
 .if defined(CFLAGS) && (${CFLAGS:M-g} != "")
 CTFFLAGS	+=	-g