Wire up exp/test-expression-parser

Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/Makefile b/Makefile
index e3941ca..7f55228 100644
--- a/Makefile
+++ b/Makefile
@@ -280,6 +280,11 @@
 lex.yy.c: exp/expression-parser.l
 	$(QUIET_CC)$(LEX) exp/expression-parser.l
 
+exp/test-expression-parser.o: exp/test-expression-parser.c
+	$(QUIET_CC)$(CC) -o $@ $(CFLAGS) $(CPPFLAGS) -c $<
+exp/test-expression-parser: exp/test-expression-parser.o
+	$(QUIET_LINK)$(CC) $(LDFLAGS) $(CFLAGS) $< y.tab.o lex.yy.o -o $@ $(LIBS)
+
 parse.o: lex.yy.o y.tab.o
 endif