toolchain: add new debugging tool using magenta_debug

toolchain/mxdbg/client/continue.c

@@ -0,0 +1,27 @@
+#include "command.h"
+
+#include <magenta/debug/packet.h>
+#include <stdio.h>
+#include <unistd.h>
+
+static int continue_impl(
+	const struct command *cmd,
+	struct debug_context *ctx,
+	int argc,
+	const char **argv,
+	void *argp)
+{
+	printf("continuing...\n");
+	struct mxdbg_packet packet;
+	mxdbg_packet_init(&packet, sizeof packet, MXDBG_PACKET_RESUME, 0);
+
+	size_t w;
+	debug_context_send_packet(ctx, &packet);
+
+	return 0;
+}
+
+const struct command cmd_continue = {
+	.cmd_name = "continue",
+	.cmd_callback = continue_impl,
+};