parser,syntax: Add separate parser for stmt with optional semicolon

Adjusting `grammar::fragments::stmt` to Optional or Yes will break
original functionality and tests.

crates/parser/src/lib.rs

@@ -88,6 +88,7 @@ pub enum FragmentKind {
     Path,
     Expr,
     Statement,
+    StatementOptionalSemi,
     Type,
     Pattern,
     Item,
@@ -118,6 +119,7 @@ pub fn parse_fragment(
         FragmentKind::Visibility => grammar::fragments::opt_visibility,
         FragmentKind::MetaItem => grammar::fragments::meta_item,
         FragmentKind::Statement => grammar::fragments::stmt,
+        FragmentKind::StatementOptionalSemi => grammar::fragments::stmt_optional_semi,
         FragmentKind::Items => grammar::fragments::macro_items,
         FragmentKind::Statements => grammar::fragments::macro_stmts,
         FragmentKind::Attr => grammar::fragments::attr,