Rollup merge of #57904 - euclio:attribute-typos, r=davidtwco

add typo suggestion to unknown attribute error

Provides a suggestion using Levenshtein distance to suggest built-in attributes and attribute macros.

Fixes #49270.

src/test/ui/issues/issue-49074.stderr

@@ -2,7 +2,7 @@ error[E0658]: The attribute `marco_use` is currently unknown to the compiler and
   --> $DIR/issue-49074.rs:3:3
    |
 LL | #[marco_use] // typo
-   |   ^^^^^^^^^
+   |   ^^^^^^^^^ help: a built-in attribute with a similar name exists: `macro_use`
    |
    = help: add #![feature(custom_attribute)] to the crate attributes to enable
 

src/test/ui/macros/macro-reexport-removed.stderr

@@ -14,7 +14,7 @@ error[E0658]: The attribute `macro_reexport` is currently unknown to the compile
   --> $DIR/macro-reexport-removed.rs:5:3
    |
 LL | #[macro_reexport(macro_one)] //~ ERROR attribute `macro_reexport` is currently unknown
-   |   ^^^^^^^^^^^^^^
+   |   ^^^^^^^^^^^^^^ help: a built-in attribute with a similar name exists: `macro_export`
    |
    = help: add #![feature(custom_attribute)] to the crate attributes to enable
 

src/test/ui/proc-macro/derive-still-gated.stderr

@@ -2,7 +2,7 @@ error[E0658]: The attribute `derive_A` is currently unknown to the compiler and
   --> $DIR/derive-still-gated.rs:8:3
    |
 LL | #[derive_A] //~ ERROR attribute `derive_A` is currently unknown
-   |   ^^^^^^^^
+   |   ^^^^^^^^ help: a built-in attribute with a similar name exists: `derive`
    |
    = help: add #![feature(custom_attribute)] to the crate attributes to enable
 

src/test/ui/suggestions/attribute-typos.rs

@@ -0,0 +1,13 @@
+#[deprcated]    //~ ERROR E0658
+fn foo() {}     //~| HELP a built-in attribute with a similar name exists
+                //~| SUGGESTION deprecated
+                //~| HELP add #![feature(custom_attribute)] to the crate attributes to enable
+
+#[tests]        //~ ERROR E0658
+fn bar() {}     //~| HELP a built-in attribute with a similar name exists
+                //~| SUGGESTION test
+                //~| HELP add #![feature(custom_attribute)] to the crate attributes to enable
+
+#[rustc_err]    //~ ERROR E0658
+fn main() {}    //~| HELP add #![feature(rustc_attrs)] to the crate attributes to enable
+                // don't suggest rustc attributes

src/test/ui/suggestions/attribute-typos.stderr

@@ -0,0 +1,27 @@
+error[E0658]: unless otherwise specified, attributes with the prefix `rustc_` are reserved for internal compiler diagnostics (see issue #29642)
+  --> $DIR/attribute-typos.rs:11:3
+   |
+LL | #[rustc_err]    //~ ERROR E0658
+   |   ^^^^^^^^^
+   |
+   = help: add #![feature(rustc_attrs)] to the crate attributes to enable
+
+error[E0658]: The attribute `tests` is currently unknown to the compiler and may have meaning added to it in the future (see issue #29642)
+  --> $DIR/attribute-typos.rs:6:3
+   |
+LL | #[tests]        //~ ERROR E0658
+   |   ^^^^^ help: a built-in attribute with a similar name exists: `test`
+   |
+   = help: add #![feature(custom_attribute)] to the crate attributes to enable
+
+error[E0658]: The attribute `deprcated` is currently unknown to the compiler and may have meaning added to it in the future (see issue #29642)
+  --> $DIR/attribute-typos.rs:1:3
+   |
+LL | #[deprcated]    //~ ERROR E0658
+   |   ^^^^^^^^^ help: a built-in attribute with a similar name exists: `deprecated`
+   |
+   = help: add #![feature(custom_attribute)] to the crate attributes to enable
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0658`.