Fix lexing of money tokens

- The polish lexer was wrongly adapted from the american one: the code to trim
  the prefix `$` char was kept instead of trimming the postfix `PLN`
- Anyway the regex isn't enforced to match until the end of input so trimming
  postfix units is not needed
- And the trimming for `€` was wrong anyway, it assumed `€` is only 1 char long
  in utf8

compiler/surface/lexer_fr.ml

@@ -318,9 +318,8 @@ let rec lex_code (lexbuf : lexbuf) : token =
       DAY
   | digit, Star (digit | hspace), Opt (',', Rep (digit, 0 .. 2)), Star hspace, 0x20AC ->
       let extract_parts = R.regexp "([0-9]([0-9 ]*[0-9]|))(,([0-9]{0,2})|)" in
-      let full_str = Utf8.lexeme lexbuf in
-      let only_numbers_str = String.trim (String.sub full_str 0 (String.length full_str - 1)) in
-      let parts = R.get_substring (R.exec ~rex:extract_parts only_numbers_str) in
+      let str = Utf8.lexeme lexbuf in
+      let parts = R.get_substring (R.exec ~rex:extract_parts str) in
       (* Integer literal*)
       let units = parts 1 in
       let remove_spaces = R.regexp " " in

compiler/surface/lexer_pl.ml

@@ -314,9 +314,8 @@ let rec lex_code (lexbuf : lexbuf) : token =
       DAY
   | digit, Star (digit | ','), Opt ('.', Rep (digit, 0 .. 2)), Star hspace, "PLN" ->
       let extract_parts = R.regexp "([0-9]([0-9,]*[0-9]|))(.([0-9]{0,2})|)" in
-      let full_str = Utf8.lexeme lexbuf in
-      let only_numbers_str = String.trim (String.sub full_str 1 (String.length full_str - 1)) in
-      let parts = R.get_substring (R.exec ~rex:extract_parts only_numbers_str) in
+      let str = Utf8.lexeme lexbuf in
+      let parts = R.get_substring (R.exec ~rex:extract_parts str) in
       (* Integer literal*)
       let units = parts 1 in
       let remove_commas = R.regexp "," in