Comment 10 for bug 180179

The type PRFuncPtr is like the void * pointer for function pointers.
PRFuncPtr is intended to be a universal function pointer type.
It should be cast to a specific function pointer type before calling
the function. So the function signature of PRFuncPtr doesn't matter.

I'm worried that the proposed change may break the compilation of
existing source code. Here is an example I made up:

PRBool foo(PRLibrary *lib, const char *name)
{
    /*
     * Instead of
     * PRFuncPtr func_ptr;
     * we declare the variable like this:
     */
    void (*func_ptr)();

    func_ptr = PR_FindFunctionSymbol(lib, name);
    return func_ptr != NULL;
}

I'm worried that changing the definition of PRFuncPtr
would make the compilation fail. We should test the
above code on all the platforms we support. I've tested
GCC on Linux and the code still compiles.