Implement getrandom syscall decoding

* getrandom.c: New file.
* Makefile.am (strace_SOURCES): Add it.
* linux/dummy.h (sys_getrandom): Remove.
* linux/syscall.h (sys_getrandom): New prototype.
* xlat/getrandom_flags.in: New file.
* tests/getrandom.c: New file.
* tests/getrandom.awk: New file.
* tests/getrandom.test: New test.
* tests/Makefile.am (check_PROGRAMS): Add getrandom.
(TESTS): Add getrandom.test.
(EXTRA_DIST): Add getrandom.awk.
* tests/.gitignore: Add getrandom.
diff --git a/getrandom.c b/getrandom.c
new file mode 100644
index 0000000..068b2e6
--- /dev/null
+++ b/getrandom.c
@@ -0,0 +1,16 @@
+#include "defs.h"
+#include "xlat/getrandom_flags.h"
+
+int
+sys_getrandom(struct tcb *tcp)
+{
+	if (exiting(tcp)) {
+		if (syserror(tcp))
+			tprintf("%#lx", tcp->u_arg[0]);
+		else
+			printstr(tcp, tcp->u_arg[0], tcp->u_rval);
+		tprintf(", %lu, ", tcp->u_arg[1]);
+		printflags(getrandom_flags, tcp->u_arg[2], "GRND_???");
+	}
+	return 0;
+}