introduce fcw macro

Author: jdonszelmann

src/bug-fix-procedure.md

@@ -113,7 +113,7 @@ store.register_future_incompatible(sess, vec![
     ...,
     FutureIncompatibleInfo {
         id: LintId::of(YOUR_ERROR_HERE),
-        reference: "issue #1234", // your tracking issue here!
+        reason: fcw!(FutureReleaseError #1234) // your tracking issue here!
     },
 ]);
 
@@ -238,7 +238,7 @@ compatibility lint":
 ```rust
 FutureIncompatibleInfo {
     id: LintId::of(OVERLAPPING_INHERENT_IMPLS),
-    reference: "issue #36889 <https://github.com/rust-lang/rust/issues/36889>",
+    reason: fcw!(FutureReleaseError #1234), // your tracking issue here!
 },
 ```
 

src/diagnostics.md

@@ -732,8 +732,7 @@ declare_lint! {
     Allow,
     "detects anonymous parameters",
     @future_incompatible = FutureIncompatibleInfo {
-        reference: "issue #41686 <https://github.com/rust-lang/rust/issues/41686>",
-        reason: FutureIncompatibilityReason::EditionError(Edition::Edition2018),
+        reason: fcw!(EditionError 2018 "slug-of-edition-guide-page")
     };
 }
 ```

src/guides/editions.md

@@ -179,8 +179,7 @@ declare_lint! {
     Allow,
     "detects edition keywords being used as an identifier",
     @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::EditionError(Edition::Edition2018),
-        reference: "issue #49716 <https://github.com/rust-lang/rust/issues/49716>",
+        reason: fcw!(EditionError 2018 "slug-of-edition-guide-page")
     };
 }
 ```