libpopcnt: add package (#4541)

packages/l/libpopcnt/xmake.lua

@@ -0,0 +1,18 @@
+package("libpopcnt")
+    set_kind("library", {headeronly = true})
+    set_homepage("https://github.com/kimwalisch/libpopcnt")
+    set_description("🚀 Fast C/C++ bit population count library")
+    set_license("BSD-2-Clause")
+
+    add_urls("https://github.com/kimwalisch/libpopcnt/archive/refs/tags/$(version).tar.gz",
+             "https://github.com/kimwalisch/libpopcnt.git")
+
+    add_versions("v3.1", "b4ea061f4c2e5385dff0dd032ad5a16c60dc0dd050391283afb463c0d62c19bd")
+
+    on_install(function (package)
+        os.cp("libpopcnt.h", package:installdir("include"))
+    end)
+
+    on_test(function (package)
+        assert(package:has_cfuncs("popcnt", {includes = "libpopcnt.h"}))
+    end)