Bump Buildroot to 2021.02-rc3 (#1260)

* Rebase patches to Buildroot 2021.02-rc3

* Update Buildroot to 2021.02-rc3

* Declare Kernel headers to be Linux version 5.10 (since they are, and new Buildroot knows about 5.10)

buildroot/support/testing/tests/package/test_lualdap.py

@@ -0,0 +1,25 @@
+from tests.package.test_lua import TestLuaBase
+
+
+class TestLuaLuaLdap(TestLuaBase):
+    config = TestLuaBase.config + \
+        """
+        BR2_PACKAGE_LUA=y
+        BR2_PACKAGE_LUALDAP=y
+        """
+
+    def test_run(self):
+        self.login()
+        self.module_test("lualdap")
+
+
+class TestLuajitLuaLdap(TestLuaBase):
+    config = TestLuaBase.config + \
+        """
+        BR2_PACKAGE_LUAJIT=y
+        BR2_PACKAGE_LUALDAP=y
+        """
+
+    def test_run(self):
+        self.login()
+        self.module_test("lualdap")