Skipping any under-the-hood initialization of the program before main() is actually called without knowing what you're doing is a bad idea.
I doubt much of anything would work correctly. argc and argv probably won't be right. Attempting to access them will probably crash. Calling malloc() will probably crash. Calling printf() will probably crash. Just returning from main() will probably crash.
Might be fun to mess with and find out exactly what happens and how to optimize the process, but whatever you find out would probably be operating system specific and then compiler specific on top of that, so perhaps it's not worth the effort.