Add long error code for error E0226

Author: Aelerinya

src/librustc_error_codes/error_codes.rs

@@ -119,6 +119,7 @@ E0222: include_str!("./error_codes/E0222.md"),
 E0223: include_str!("./error_codes/E0223.md"),
 E0224: include_str!("./error_codes/E0224.md"),
 E0225: include_str!("./error_codes/E0225.md"),
+E0226: include_str!("./error_codes/E0226.md"),
 E0229: include_str!("./error_codes/E0229.md"),
 E0230: include_str!("./error_codes/E0230.md"),
 E0231: include_str!("./error_codes/E0231.md"),
@@ -475,7 +476,6 @@ E0751: include_str!("./error_codes/E0751.md"),
 //  E0217, // ambiguous associated type, defined in multiple supertraits
 //  E0218, // no associated type defined
 //  E0219, // associated type defined in higher-ranked supertrait
-    E0226, // only a single explicit lifetime bound is permitted
     E0227, // ambiguous lifetime bound, explicit lifetime bound required
     E0228, // explicit lifetime bound required
 //  E0233,

src/librustc_error_codes/error_codes/E0226.md

@@ -0,0 +1,20 @@
+Only a single explicit lifetime bound is permitted on trait objects.
+
+Example of erroneous code:
+
+```compile_fail
+trait Foo {}
+
+type T<'a, 'b> = dyn Foo + 'a + 'b; // error: Trait object `arg` has two
+                                    //        lifetime bound, 'a and 'b.
+```
+
+Here `T` is a trait object with two explicit lifetime bounds, 'a and 'b.
+
+To fix this error, consider removing one of the lifetime bounds:
+
+```
+trait Foo {}
+
+type T<'a> = dyn Foo + 'a;
+```

src/test/ui/regions/region-bounds-on-objects-and-type-parameters.stderr

@@ -31,5 +31,5 @@ LL | struct Foo<'a,'b,'c> {
 
 error: aborting due to 3 previous errors
 
-Some errors have detailed explanations: E0392, E0478.
-For more information about an error, try `rustc --explain E0392`.
+Some errors have detailed explanations: E0226, E0392, E0478.
+For more information about an error, try `rustc --explain E0226`.