Use CXX to link fuzzer, also link with $FUZZLIB

--HG--
branch : fuzz

Makefile.in

@@ -231,7 +231,7 @@ svrfuzzobjs=$(subst svr-main.o, ,$(dropbearobjs))
 CLANG=clang
 
 # fuzzers that don't use libfuzzer, just a standalone harness that feeds inputs
-fuzzstandalone: LIBS+=fuzz-harness.o
+fuzzstandalone: FUZZLIB=fuzz-harness.o
 fuzzstandalone: fuzz-harness.o fuzzers
 
 # build all the fuzzers. This will require fail to link unless built with
@@ -240,7 +240,7 @@ fuzzstandalone: fuzz-harness.o fuzzers
 fuzzers: fuzzer-preauth
 
 fuzzer-preauth: fuzzer-preauth.o $(HEADERS) $(LIBTOM_DEPS) Makefile $(svrfuzzobjs)
-	$(CC) $@.o $(LDFLAGS) $(svrfuzzobjs) -o $@$(EXEEXT) $(LIBTOM_LIBS) $(LIBS) @CRYPTLIB@
+	$(CXX) $(CXXFLAGS) $@.o $(LDFLAGS) $(svrfuzzobjs) -o $@$(EXEEXT) $(LIBTOM_LIBS) $(LIBS) $(FUZZLIB) @CRYPTLIB@
 
 # run this to update hardcoded hostkeys for for fuzzing. 
 # hostkeys.c is checked in to hg.