fix #101626, suggest pub instead of public for const type item

compiler/rustc_ast/src/token.rs

@@ -473,6 +473,7 @@ pub fn can_begin_item(&self) -> bool {
                 kw::Extern,
                 kw::Impl,
                 kw::Unsafe,
+                kw::Const,
                 kw::Static,
                 kw::Union,
                 kw::Macro,

src/test/ui/parser/public-instead-of-pub-3.fixed

@@ -0,0 +1,9 @@
+// run-rustfix
+mod test {
+    pub const X: i32 = 123;
+    //~^ ERROR expected one of `!` or `::`, found keyword `const`
+}
+
+fn main() {
+    println!("{}", test::X);
+}

src/test/ui/parser/public-instead-of-pub-3.rs

@@ -0,0 +1,9 @@
+// run-rustfix
+mod test {
+    public const X: i32 = 123;
+    //~^ ERROR expected one of `!` or `::`, found keyword `const`
+}
+
+fn main() {
+    println!("{}", test::X);
+}

src/test/ui/parser/public-instead-of-pub-3.stderr

@@ -0,0 +1,13 @@
+error: expected one of `!` or `::`, found keyword `const`
+  --> $DIR/public-instead-of-pub-3.rs:3:12
+   |
+LL |     public const X: i32 = 123;
+   |            ^^^^^ expected one of `!` or `::`
+   |
+help: write `pub` instead of `public` to make the item public
+   |
+LL |     pub const X: i32 = 123;
+   |     ~~~
+
+error: aborting due to previous error
+