[Tolk] Compilation pipeline, register global symbols in advance

Since I've implemented AST, now I can drop forward declarations.
Instead, I traverse AST of all files and register global symbols
(functions, constants, global vars) as a separate step, in advance.

That's why, while converting AST to Expr/Op, all available symbols are
already registered.
This greatly simplifies "intermediate state" of yet unknown functions
and checking them afterward.

Redeclaration of local variables (inside the same scope)
is now also prohibited.

Author: tolk-vm

crypto/smartcont/mathlib.tolk

@@ -676,7 +676,7 @@ int fixed248::pow(int x, int y) inline_ref {
   if (sq <= 0) {
     return - (sq == 0);   ;; underflow
   }
-  int y = expm1_f257(mulrshiftr256(ll, log2_const_f256()));
+  y = expm1_f257(mulrshiftr256(ll, log2_const_f256()));
   return (y ~>> (9 - q)) - (-1 << sq);
 }
 

tolk/CMakeLists.txt

@@ -7,7 +7,12 @@ set(TOLK_SOURCE
         compiler-state.cpp
         ast.cpp
         ast-from-tokens.cpp
-        ast-to-legacy.cpp
+        pipe-discover-parse-sources.cpp
+        pipe-handle-pragmas.cpp
+        pipe-register-symbols.cpp
+        pipe-ast-to-legacy.cpp
+        pipe-find-unused-symbols.cpp
+        pipe-generate-fif-output.cpp
         unify-types.cpp
         abscode.cpp
         gen-abscode.cpp