gc: fix msvc not using libatomic_ops (#15418)

thirdparty/libatomic_ops/atomic_ops/sysdeps/sunc/sparc.h

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2004 Hewlett-Packard Development Company, L.P.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "../all_atomic_load_store.h"
+
+/* Real SPARC code uses TSO:                            */
+#include "../ordered_except_wr.h"
+
+/* Test_and_set location is just a byte.                */
+#include "../test_and_set_t_is_char.h"
+
+#ifdef __cplusplus
+  extern "C" {
+#endif
+
+extern AO_TS_VAL_t
+AO_test_and_set_full(volatile AO_TS_t *addr);
+/* Implemented in separate .S file, for now.    */
+#define AO_HAVE_test_and_set_full
+
+/* TODO: Like the gcc version, extend this for V8 and V9.   */
+
+#ifdef __cplusplus
+  } /* extern "C" */
+#endif