LibJS: Reorganize tests into subfolders

Author: https://github.com/mattco98
Commit: 4c48c9d69d
Pull-request: https://github.com/SerenityOS/serenity/pull/2681
Reviewed-by: https://github.com/linusg

Libraries/LibJS/Tests/builtins/Math/Math.trunc.js

@@ -0,0 +1,18 @@
+load("test-common.js")
+
+try {
+    assert(Math.trunc(13.37) === 13);
+    assert(Math.trunc(42.84) === 42);
+    assert(Math.trunc(0.123) ===  0);
+    assert(Math.trunc(-0.123) === -0);
+
+    assert(isNaN(Math.trunc(NaN)));
+    assert(isNaN(Math.trunc('foo')));
+    assert(isNaN(Math.trunc()));
+
+    assert(Math.trunc.length === 1);
+
+    console.log("PASS");
+} catch (e) {
+    console.log("FAIL: " + e);
+}