LibJS: Add Math.{cos,sin,tan}()

Author: https://github.com/linusg
Commit: f5dacfbb5b
Pull-request: https://github.com/SerenityOS/serenity/pull/1659

Libraries/LibJS/Tests/Math.tan.js

@@ -0,0 +1,16 @@
+try {
+    assert(Math.tan(0) === 0);
+    assert(Math.tan(null) === 0);
+    assert(Math.tan('') === 0);
+    assert(Math.tan([]) === 0);
+    assert(Math.ceil(Math.tan(Math.PI / 4)) === 1);
+    assert(isNaN(Math.tan()));
+    assert(isNaN(Math.tan(undefined)));
+    assert(isNaN(Math.tan([1, 2, 3])));
+    assert(isNaN(Math.tan({})));
+    assert(isNaN(Math.tan("foo")));
+
+    console.log("PASS");
+} catch (e) {
+    console.log("FAIL: " + e);
+}