In case source files are compiled with -g, tell clang not to emit .cfi

directives, since on sparc64 we must still GNU as, which does not
support those directives.

Note there are several programs and libraries in our tree, which are
always compiled with -g, even if DEBUG_FLAGS is not set by the user!

share/mk/bsd.sys.mk

@@ -120,6 +120,10 @@ CLANG_NO_IAS=	 -no-integrated-as
 CLANG_OPT_SMALL= -mstack-alignment=8 -mllvm -inline-threshold=3\
 		 -mllvm -enable-load-pre=false -mllvm -simplifycfg-dup-ret
 CFLAGS+=	 -Qunused-arguments
+.if ${MACHINE_CPUARCH} == "sparc64"
+# Don't emit .cfi directives, since we must use GNU as on sparc64, for now.
+CFLAGS+=	 -fno-dwarf2-cfi-asm
+.endif # SPARC64
 CFLAGS+=	 ${CFLAGS.clang}
 CXXFLAGS+=	 ${CXXFLAGS.clang}
 .else # !CLANG