Rename match to match_text for lexer user code blocks

spec/json_parser.rust.propane

@@ -60,7 +60,7 @@ token rbracket /\]/;
 token comma /,/;
 token colon /:/;
 token number /-?(0|[1-9][0-9]*)(\.[0-9]+)?([eE][-+]?[0-9]+)?/ <<
-    let n: f64 = std::str::from_utf8(match_).unwrap().parse().unwrap();
+    let n: f64 = std::str::from_utf8(match_text).unwrap().parse().unwrap();
     $$ = JSONValue::Number(n);
 >>
 token true <<
@@ -106,11 +106,11 @@ string: /\\t/ <<
 >>
 string: /\\u[0-9a-fA-F]{4}/ <<
   /* Not actually going to encode the code point for this example... */
-  let s: String = ['{', match_[2] as char, match_[3] as char, match_[4] as char, match_[5] as char, '}'].iter().collect();
+  let s: String = ['{', match_text[2] as char, match_text[3] as char, match_text[4] as char, match_text[5] as char, '}'].iter().collect();
   ${context.string_value}.push_str(&s);
 >>
 string: /[^\\]/ <<
-  ${context.string_value}.push(match_[0] as char);
+  ${context.string_value}.push(match_text[0] as char);
 >>
 Start -> Value <<
   $$ = $1;