[cost] Add .PHONY in cost.make

Reviewed By: jberdine

Differential Revision: D22002143

fbshipit-source-id: dd036d5d4

infer/tests/cost.make

@@ -10,6 +10,7 @@ cost-issues.exp.test$(TEST_SUFFIX): $(INFER_OUT)/report.json $(INFER_BIN) issues
 
 test: cost-test
 
+.PHONY: cost-test
 cost-test: cost-issues.exp.test$(TEST_SUFFIX)
 	$(QUIET)cd $(TESTS_DIR) && \
 	$(call check_no_diff,$(TEST_REL_DIR)/cost-issues.exp,$(TEST_REL_DIR)/cost-issues.exp.test$(TEST_SUFFIX))
@@ -17,11 +18,13 @@ cost-test: cost-issues.exp.test$(TEST_SUFFIX)
 
 replace: cost-replace
 
+.PHONY: cost-replace
 cost-replace: cost-issues.exp.test$(TEST_SUFFIX)
 	    cp $< cost-issues.exp$(TEST_RESULT_SUFFIX)
 
 
 clean: cost-clean
 
+.PHONY: cost-clean
 cost-clean:
 	$(REMOVE) cost-issues.exp.test$(TEST_SUFFIX)