Moved all packages in core, base, vendor, tests and examples to use new #+ file tag syntax.

vendor/directx/dxc/dxcdef_unix.odin

@@ -1,4 +1,4 @@
-//+build linux, darwin, freebsd, openbsd, netbsd
+#+build linux, darwin, freebsd, openbsd, netbsd
 package directx_dxc
 import "core:c"
 

vendor/directx/dxc/dxcdef_windows.odin

@@ -1,4 +1,4 @@
-//+build windows
+#+build windows
 package directx_dxc
 import win32 "core:sys/windows"
 import dxgi "vendor:directx/dxgi"