xfail-fast regions-mock-tcx.rs

src/test/run-pass/regions-mock-tcx.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// xfail-fast `use` standards don't resolve
+
 // Test a sample usage pattern for regions. Makes use of the
 // following features:
 //