- fixed incorrect extension of overridden function prototype

Prototype of overridden function with optional argument(s) missing could extend unrelated prototype of previously defined function when their arguments and return value(s) match

https://forum.zdoom.org/viewtopic.php?t=71340

src/common/scripting/frontend/zcc_compile.cpp

@@ -2486,6 +2486,8 @@ void ZCCCompiler::CompileFunction(ZCC_StructWork *c, ZCC_FuncDeclarator *f, bool
 							{
 								newfunc->ArgFlags.Push(sym->Variants[0].ArgFlags[i]);
 							}
+
+							newfunc->Proto = sym->Variants[0].Proto;
 						}
 					}
 				}