Using --as-needed here eliminates the libelf linkage,
which results in undefined symbols at runtime.

--- a/cxxfilt/Makefile
+++ b/cxxfilt/Makefile
@@ -8,7 +8,7 @@ SRCS=	cxxfilt.c
 WARNS?=	6
 
 DPADD=	${LIBELFTC} ${LIBELF}
-LDADD=	-lelftc -lelf
+LDADD=	-Wl,--no-as-needed -lelftc -lelf
 
 MAN1=	c++filt.1