add libdill (#1719)

* add libdill

* Update xmake.lua

packages/l/libdill/xmake.lua

@@ -0,0 +1,21 @@
+package("libdill")
+    set_homepage("https://github.com/sustrik/libdill")
+    set_description("Structured concurrency in C")
+    set_license("MIT")
+
+    add_urls("https://github.com/sustrik/libdill.git")
+    add_versions("2022.08.10", "32d0e8b733416208e0412a56490332772bc5c6e1")
+
+    add_deps("cmake")
+    add_deps("openssl")
+
+    on_install("macosx", "linux", function (package)
+        local configs = {"-DBUILD_TESTING=OFF"}
+        table.insert(configs, "-DCMAKE_BUILD_TYPE=" .. (package:debug() and "Debug" or "Release"))
+        table.insert(configs, "-DBUILD_SHARED_LIBS=" .. (package:config("shared") and "ON" or "OFF"))
+        import("package.tools.cmake").install(package, configs, {packagedeps = "openssl"})
+    end)
+
+    on_test(function (package)
+        assert(package:has_cfuncs("dill_tcp_listen", {includes = "libdill.h"}))
+    end)