erlang: Allow custom erlc flags for the test suite

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@990960 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/test/erl/Makefile b/test/erl/Makefile
index 2126037..3fc8fe5 100644
--- a/test/erl/Makefile
+++ b/test/erl/Makefile
@@ -55,11 +55,11 @@
 ${GEN_TARGETDIR}/: ${GENDIR}/
 	rm -rf ${GEN_TARGETDIR}
 	mkdir -p ${GEN_TARGETDIR}
-	erlc ${INCLUDEFLAGS} -o ${GEN_TARGETDIR} ${GEN_SRCDIR}/*.erl
+	erlc ${ERLC_FLAGS} ${INCLUDEFLAGS} -o ${GEN_TARGETDIR} ${GEN_SRCDIR}/*.erl
 
 $(TARGETS): ${TARGETDIR}/%.beam: ${SRCDIR}/%.erl ${GEN_INCLUDEDIR}/ ${HEADERS}
 	mkdir -p ${TARGETDIR}
-	erlc ${INCLUDEFLAGS} -o ${TARGETDIR} $<
+	erlc ${ERLC_FLAGS} ${INCLUDEFLAGS} -o ${TARGETDIR} $<
 
 clean:
 	rm -f ${TARGETDIR}/*.beam