Semicolon Cleanup

1. Semicolons were required in the wrong spot.
2. Make semicolons "invisible" (from the tree-sitter perspective).

Signed-off-by: Will Hawkins <hawkinsw@obs.cr>

tree-sitter-p4/test.txt

@@ -1,16 +1,7 @@
       parser main_parser() {
-        state next_state {
-          transition reject;
-        }
-        state not_next_state {
-          transition reject;
-        }
         state start {
-          transition starts;
-        }
-        state starts {
-          transition select (se) {
-            true: next_state;
-          };
+          bool where_to = true;
+          string where_from = where_to;
+          transition reject;
         }
       };