Use revisions instead of two separate tests

Author: benschulz

tests/ui/lint/unused/unused-parens-trait-obj-e2015.rs

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+//@ revisions: edition2015 edition2018
+//@[edition2015] check-pass
+//@[edition2015] edition: 2015
+//@[edition2018] run-rustfix
+//@[edition2018] edition: 2018
+
+#![deny(unused_parens)]
+
+#[allow(unused)]
+macro_rules! edition2015_only {
+    () => {
+        mod dyn {
+            pub type IsAContextualKeywordIn2015 = ();
+        }
+
+        pub type DynIsAContextualKeywordIn2015A = dyn::IsAContextualKeywordIn2015;
+    }
+}
+
+#[cfg(edition2015)]
+edition2015_only!();
+
+// there's a lint for 2018 and later only because of how dyn is parsed in edition 2015
+//[edition2018]~v ERROR unnecessary parentheses around type
+pub type DynIsAContextualKeywordIn2015B = Box<dyn ::std::ops::Fn()>;
+
+fn main() {}

tests/ui/lint/unused/unused-parens-trait-obj-e2018-and-after.fixed

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+error: unnecessary parentheses around type
+  --> $DIR/unused-parens-trait-obj.rs:25:51
+   |
+LL | pub type DynIsAContextualKeywordIn2015B = Box<dyn (::std::ops::Fn())>;
+   |                                                   ^                ^
+   |
+note: the lint level is defined here
+  --> $DIR/unused-parens-trait-obj.rs:7:9
+   |
+LL | #![deny(unused_parens)]
+   |         ^^^^^^^^^^^^^
+help: remove these parentheses
+   |
+LL - pub type DynIsAContextualKeywordIn2015B = Box<dyn (::std::ops::Fn())>;
+LL + pub type DynIsAContextualKeywordIn2015B = Box<dyn ::std::ops::Fn()>;
+   |
+
+error: aborting due to 1 previous error
+

tests/ui/lint/unused/unused-parens-trait-obj-e2018-and-after.rs

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+//@ revisions: edition2015 edition2018
+//@[edition2015] check-pass
+//@[edition2015] edition: 2015
+//@[edition2018] run-rustfix
+//@[edition2018] edition: 2018
+
+#![deny(unused_parens)]
+
+#[allow(unused)]
+macro_rules! edition2015_only {
+    () => {
+        mod dyn {
+            pub type IsAContextualKeywordIn2015 = ();
+        }
+
+        pub type DynIsAContextualKeywordIn2015A = dyn::IsAContextualKeywordIn2015;
+    }
+}
+
+#[cfg(edition2015)]
+edition2015_only!();
+
+// there's a lint for 2018 and later only because of how dyn is parsed in edition 2015
+//[edition2018]~v ERROR unnecessary parentheses around type
+pub type DynIsAContextualKeywordIn2015B = Box<dyn (::std::ops::Fn())>;
+
+fn main() {}