Rename match to match_text for lexer user code blocks

spec/rewind.rust.propane

@@ -56,7 +56,7 @@ token rbrace /\}/;
 token plus /\+/;
 token num /\d+/ <<
   let mut v: i64 = 0;
-  for c in match_ { v = v * 10 + (*c - b'0') as i64; }
+  for c in match_text { v = v * 10 + (*c - b'0') as i64; }
   $$ = v;
 >>