Add NASM Helloworld support for Win32

This is an example using libc, this program can be successfully built in MinGW environment.

assembler_nasm_win32.asm

@@ -0,0 +1,10 @@
+BITS	32
+global	_main
+extern	_printf
+section	.text
+	push	msg
+	call	_printf
+	add		esp,4
+	ret
+section	.data
+	msg:	db	"Hello world",0Ah,0