No error reported to user when segfault occurs with windows Subsystem

[marler8997]

The following application will produce an access violation on windows, and when compiling with the "windows" subsystem, will not report any error to the user:

const std = @import("std");
const w = std.os.windows;

pub extern "user32" fn MessageBoxA (
    hWnd: ?w.HWND,
    lpText: [*:0]const u8,
    lpCaption: [*:0]const u8,
    uType: u32,
) callconv(w.WINAPI) c_int;

pub export fn wWinMainCRTStartup() callconv(w.WINAPI) noreturn {
    // comment out the next line to show that the program works and produces a message box
    (@intToPtr(fn() void, 1))();
    _ = MessageBoxA(null, "Hello", "We are here", 0);
    w.kernel32.ExitProcess(0);
}

Here's how to build:

zig build-exe bug.zig --single-threaded --subsystem windows

Note that when the --subsystem windows arguments are removed, it will popup an error window and provide the user a chance to debug the problem. The problem is that when using the "windows" subsystem, process just dies with no information and no error reported to the user.