musl: provide several missing definitions for prctl()

src/include/musl/sys/prctl.h

@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include_next <sys/prctl.h>     /* IWYU pragma: export */
+
+/* musl's sys/prctl.h does not include linux/prctl.h, and also we cannot include with linux/prctl.h.
+ * Hence, we need to provide some missing definitions. */
+
+#ifndef PR_SET_MDWE
+#define PR_SET_MDWE  65
+#endif
+
+#ifndef PR_MDWE_REFUSE_EXEC_GAIN
+#define PR_MDWE_REFUSE_EXEC_GAIN  (1UL << 0)
+#endif
+
+#ifndef PR_SET_MEMORY_MERGE
+#define PR_SET_MEMORY_MERGE  67
+#endif