Fix Windows build with WAF

vgui2/src/wscript

@@ -28,9 +28,6 @@ def build(bld):
 		'MemoryBitmap.cpp',
 		'MessageListener.cpp',
 		'Scheme.cpp',
-		#'Surface.cpp',					[$WIN32]
-		#'System.cpp',					[$WINDOWS||$X360]
-		'system_posix.cpp',# [$POSIX]
 		'../../public/UnicodeFileHelpers.cpp',
 		'vgui.cpp',
 		'vgui_internal.cpp',
@@ -40,6 +37,17 @@ def build(bld):
 		'keyrepeat.cpp'
 	]
 
+	if bld.env.DEST_OS == 'win32':
+		source += [
+			'Surface.cpp',
+			'System.cpp',
+			'../../public/tier0/memoverride.cpp'
+		]
+	else:
+		source += [
+			'system_posix.cpp'
+		]
+		
 	includes = [
 		'.',
 		'../../public',
@@ -52,6 +60,9 @@ def build(bld):
 
 	libs = ['tier0','tier1','tier2','tier3','vstdlib','SDL2']
 
+	if bld.env.DEST_OS == 'win32':
+		libs += ['USER32', 'IMM32', 'GDI32', 'SHELL32', 'OLE32', 'SHLWAPI', 'vgui_surfacelib', 'WINMM']
+		
 	install_path = bld.env.LIBDIR
 
 	bld.shlib(