Implement functions to get stdin, stdout & stderr

src/os/file/win/file_win.c

@@ -54,6 +54,24 @@ wapp_intern DWORD file_seek_origins[FILE_SEEK_ORIGIN_COUNT] = {
 	[WAPP_SEEK_END]     = FILE_END,
 };
 
+WFile *wapp_file_stdin(void) {
+	wapp_persist WFile _stdin  = { .fh = INVALID_HANDLE_VALUE };
+	_stdin.fh = GetStdHandle(STD_INPUT_HANDLE);
+	return &_stdin;
+}
+
+WFile *wapp_file_stdout(void) {
+	wapp_persist WFile _stdout = { .fh = INVALID_HANDLE_VALUE };
+	_stdout.fh = GetStdHandle(STD_OUTPUT_HANDLE);
+	return &_stdout;
+}
+
+WFile *wapp_file_stderr(void) {
+	wapp_persist WFile _stderr = { .fh = INVALID_HANDLE_VALUE };
+	_stderr.fh = GetStdHandle(STD_ERROR_HANDLE);
+	return &_stderr;
+}
+
 WFile *_file_open(const Allocator *allocator, Str8RO *filepath, FileAccessMode mode) {
 	wapp_persist c8 tmp[WAPP_PATH_MAX] = {0};
 	memset(tmp, 0, WAPP_PATH_MAX);