[Tolk] Rewrite lexer, spaces are not mandatory anymore

A new lexer is noticeably faster and memory efficient
(although splitting a file to tokens is negligible in a whole pipeline).

But the purpose of rewriting lexer was not just to speed up,
but to allow writing code without spaces:
`2+2` is now 4, not a valid identifier as earlier.

The variety of symbols allowed in identifier has greatly reduced
and is now similar to other languages.

SrcLocation became 8 bytes on stack everywhere.

Command-line flags were also reworked:
- the input for Tolk compiler is only a single file now, it's parsed, and parsing continues while new #include are resolved
- flags like -A -P and so on are no more needed, actually

crypto/smartcont/mathlib.tolk

@@ -572,9 +572,9 @@ int atanh_f261(int x, int n) inline_ref {
     s -= 1;
   }
   x += t;
-  int 2x = 2 * x;
-  int y = lshift256divr(2x, (x >> 1) - t);
-  ;; y = 2x - (mulrshiftr256(2x, y) ~>> 2);  ;; this line could improve precision on very rare occasions
+  int `2x` = 2 * x;
+  int y = lshift256divr(`2x`, (x >> 1) - t);
+  ;; y = `2x` - (mulrshiftr256(2x, y) ~>> 2);  ;; this line could improve precision on very rare occasions
   return (atanh_f258(y, 36), s);
 }