move utf8_idents

Author: mejrs

tests/ui/utf8_idents.rs renamed to tests/ui/rfcs/rfc-2457-non-ascii-idents/utf8_idents.rs

@@ -1,14 +1,13 @@
+//! 'Check that non-ascii-idents are allowed.
+
 //@ check-pass
 //
 #![allow(mixed_script_confusables, non_camel_case_types)]
 
-fn foo<
-    'β,
-    γ
->() {}
+fn foo<'β, γ>() {}
 
 struct X {
-    δ: usize
+    δ: usize,
 }
 
 pub fn main() {