Rustc generates wrong calling convention for WinMain

[klutzy]

Currently rustc generates WinMain function with cdecl calling convention (src/librustc/middle/trans/base.rs), but Win32 API docs say stdcall is right.
Linker works because we actually export it as "WinMain@16", but I think it's a hack and should be fixed.

[brson]

Interesting!

[klutzy]

After some investigation: it is okay to use main for mingw gcc. It's independent of gui/console (see note below).
I've patched locally to use main regardless of platform (except for android who use amain), and built stage2 with no problem. I'll make pr after make check-fast.

Note on GUI:

for gcc: to make GUI rust application, pass --link-args "-Wl,--subsystem,windows" to rustc. It is independent to this issue; it works already. (example)
More info: http://gcc.gnu.org/ml/gcc-help/2004-01/msg00223.html

for msvc (#1768): winsdk linker accepts /subsystem:{console,windows} for console/gui configuration. However, linker tries to find only one of main/WinMain depending on the option.
But it is possible to override by passing /entry:{mainCRTStartup,WinMainCRTStartup} to linker, so it is not a big problem.