Add tests from vibe-d:core.

tests/vibe.core.net.1376.d

@@ -0,0 +1,42 @@
+/+ dub.sdl:
+	name "tests"
+	description "TCP disconnect task issue"
+	dependency "vibe-core" path="../"
+	versions "VibeDefaultMain"
++/
+module test;
+
+import vibe.core.core;
+import vibe.core.net;
+import core.time : msecs;
+
+shared static this()
+{
+	listenTCP(11375,(conn){
+		auto td = runTask!TCPConnection((conn) {
+			ubyte [3] buf;
+			try {
+				conn.read(buf);
+				assert(false, "Expected read() to throw an exception.");
+			} catch (Exception) {} // expected
+		}, conn);
+		sleep(10.msecs);
+		conn.close();
+	});
+
+	runTask({
+		try {
+			auto conn = connectTCP("127.0.0.1", 11375);
+			conn.write("a");
+			conn.close();
+		} catch (Exception e) assert(false, e.msg);
+
+		try {
+			auto conn = connectTCP("127.0.0.1", 11375);
+			conn.close();
+		} catch (Exception e) assert(false, e.msg);
+
+		sleep(50.msecs);
+		exitEventLoop();
+	});
+}