update pat2015/2021 parts

src/macros-by-example.md

@@ -28,7 +28,7 @@
 >
 > _MacroFragSpec_ :\
 >       `block` | `expr` | `ident` | `item` | `lifetime` | `literal`\
->    | `meta` | `pat` | `pat2015` | `pat2021` | `path` | `stmt` | `tt` | `ty` | `vis`
+>    | `meta` | `pat` | `pat_param`  | `path` | `stmt` | `tt` | `ty` | `vis`
 >
 > _MacroRepSep_ :\
 > &nbsp;&nbsp; [_Token_]<sub>_except delimiters and repetition operators_</sub>
@@ -122,9 +122,8 @@ fragment specifiers are:
   * `block`: a [_BlockExpression_]
   * `stmt`: a [_Statement_] without the trailing semicolon (except for item
     statements that require semicolons)
-  * `pat2015`: a [_PatternNoTopAlt_]
-  * `pat2021`: a [_Pattern_]
-  * `pat`: equivalent to either `pat2015` or `pat2021`, depending on edition (see note below).
+  * `pat_param`: a [_PatternNoTopAlt_]
+  * `pat`: equivalent to `pat_param`
   * `expr`: an [_Expression_]
   * `ty`: a [_Type_]
   * `ident`: an [IDENTIFIER_OR_KEYWORD]
@@ -135,11 +134,6 @@ fragment specifiers are:
   * `vis`: a possibly empty [_Visibility_] qualifier
   * `literal`: matches `-`<sup>?</sup>[_LiteralExpression_]
 
-> **Edition Differences**: In Editions 2015 and 2018, `pat` fragment-specifiers
-> do not allow top-level or-patterns (i.e. they accept [_PatternNoTopAlt_]). In
-> Edition 2021, this was changed so that top-level or-patterns are accepted by
-> `pat` (i.e. [_Pattern_]).
-
 In the transcriber, metavariables are referred to simply by `$`_name_, since
 the fragment kind is specified in the matcher. Metavariables are replaced with
 the syntax element that matched them. The keyword metavariable `$crate` can be
@@ -495,7 +489,6 @@ For more detail, see the [formal specification].
 [_Item_]: items.md
 [_LiteralExpression_]: expressions/literal-expr.md
 [_MetaListIdents_]: attributes.md#meta-item-attribute-syntax
-[_Pattern_]: patterns.md
 [_PatternNoTopAlt_]: patterns.md
 [_Statement_]: statements.md
 [_TokenTree_]: macros.md#macro-invocation