Add diagnostics for semicolon at the end of for loop

This change introduce diagnostics when there is a semicolon at
the end of the for..do loop body:
```cpp
  for v* | all next log() do :(e) = {
    foo();
    bar*;
  };
```
generates:
```
error: for..do loop body shall not end with a semicolon (at ';')
```

Author: filipsajdak

source/parse.h

@@ -4157,6 +4157,11 @@ class parser
                 n->for_with_in = true;
             }
 
+            if (!done() && curr().type() == lexeme::Semicolon) {
+                error("for..do loop body shall not end with a semicolon");
+                return {};
+            }
+
             return n;
         }