auto merge of #8688 : alexcrichton/rust/fix, r=graydon

mk/tests.mk

@@ -240,6 +240,8 @@ tidy:
 		@$(call E, check: formatting)
 		$(Q)find $(S)src -name '*.r[sc]' \
 		| grep '^$(S)src/test' -v \
+		| grep '^$(S)src/libuv' -v \
+		| grep '^$(S)src/llvm' -v \
 		| xargs -n 10 $(CFG_PYTHON) $(S)src/etc/tidy.py
 		$(Q)find $(S)src/etc -name '*.py' \
 		| xargs -n 10 $(CFG_PYTHON) $(S)src/etc/tidy.py