Respect CFLAGS, LDFLAGS, and AR.

The better way to fix AR would be to patch configure.in,
but it is sufficiently old to fail with current autotools.
--- Makefile.in
+++ Makefile.in
@@ -27,7 +27,6 @@
 YACC = @YACC@
 SSLEAY = @SSLEAY@
 RM = @RM@
-AR = @AR@
 NROFF = @NROFF@
 TAR = @TAR@
 TRUE = @TRUE@
@@ -41,10 +40,10 @@
 YACCFLAGS = -d -p kn -b k
 LEXFLAGS2 = -Pkv -s -i
 LEXFLAGS = -Cr -Pkn -s -i
-CFLAGS = -O2 -Wall # -g
 RMFLAGS2 = -rf
 RMFLAGS = -f
 NROFFFLAGS = -mandoc
+LDFLAGS = @LDFLAGS@
 
 SSLCONF = testsuite/openssl.cnf
 SSLCERT = testsuite/test.cert.pem
@@ -83,7 +82,7 @@
 	$(RANLIB) $(TARGET)
 
 $(TARGET2): $(TARGET) $(OBJS2)
-	$(CC) $(CFLAGS) -o $(TARGET2) $(OBJS2) $(LIBS)
+	$(CC) $(CFLAGS) $(LDFLAGS) -o $(TARGET2) $(OBJS2) $(LIBS)
 
 k.tab.c: keynote.y header.h keynote.h assertion.h config.h
 	$(YACC) $(YACCFLAGS) keynote.y
@@ -131,7 +130,7 @@
 	-keyout $(SSLKEY)
 
 test-sample: all $(OBJS3)
-	$(CC) $(CFLAGS) -o $(TARGET3) $(OBJS3) $(LIBS)
+	$(CC) $(CFLAGS) $(LDFLAGS) -o $(TARGET3) $(OBJS3) $(LIBS)
 
 test-sig: all $(SSLCERT) $(SSLKEY)
 	$(SED) -e 's/--.*//' < $(SSLCERT) > $(SSLCERT).1