Assertion at analyze.cpp:5576 when compiling -- implicit cast to *c_void problem

[wilsonk]

This may be a duplicate of #4246 (or just similar) but I ran int an error when trying to use SDL audio ala:

pub usingnamespace @cImport({
     @cInclude("SDL.h");
     @cDefine("SDL_WINDOWPOS_UNDEFINED", "0x1fff000");
 });
 
 const SdlAudioRingBuffer = struct {
     size: usize,
     write_cursor: usize,
     play_cursor: usize,
     data: [*]u8,
 };
 
 var AudioRingBuffer: SdlAudioRingBuffer = undefined;
 pub fn SDLAudioCallback(user_data: ?*c_void, audio_data: ?[*]u8, length: c_int) callconv(.C) void {}
 
 test "bad implicit cast to extern *c_void" {
     var audio_settings: SDL_AudioSpec = undefined;
 
     audio_settings.freq = @intCast(c_int, 1);
     audio_settings.format = 32784;
     audio_settings.channels = 2;
     audio_settings.samples = 1024;
     audio_settings.callback = SDLAudioCallback;
     audio_settings.userdata = &AudioRingBuffer; // works with explicit cast - @ptrCast(*c_void, &AudioRingBuffer);
 
     return;
 }

Hopefully this is minimized enough. Of course, I am just working around the problem with the explicit
cast, as per the comment in the code.

Thanks