fix: return values from lua_yield and lua_break

they return a value which can be returned from a lua call (its -1, indicating a status change i guess)

Author: mworzala

src/main/java/net/hollowcube/luau/LuaState.java

@@ -199,8 +199,8 @@ Set Functions (Stack -> Lua)
     Coroutine Functions
      */
 
-    void yield(int resultCount);
-    void break_();
+    int yield(int resultCount);
+    int break_();
     @NotNull LuaStatus resume(@NotNull LuaState from, int argCount);
     @NotNull LuaStatus resumeError(@NotNull LuaState from);
     @NotNull LuaStatus status();

src/main/java/net/hollowcube/luau/LuaStateImpl.java

@@ -665,15 +665,13 @@ public void pcall(int argCount, int resultCount) {
     }
 
     @Override
-    public void yield(int resultCount) {
-        // lua_yield does return an int, but its always -1.
-        lua_yield(L, resultCount);
+    public int yield(int resultCount) {
+        return lua_yield(L, resultCount);
     }
 
     @Override
-    public void break_() {
-        // lua_break does return an int, but its always -1.
-        lua_break(L);
+    public int break_() {
+        return lua_break(L);
     }
 
     @Override