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/String/String.fromCharCode.js

@@ -0,0 +1,23 @@
+load("test-common.js");
+
+try {
+    assert(String.fromCharCode.length === 1);
+    
+    assert(String.fromCharCode() === "");
+    assert(String.fromCharCode(0) === "\u0000");
+    assert(String.fromCharCode(false) === "\u0000");
+    assert(String.fromCharCode(null) === "\u0000");
+    assert(String.fromCharCode(undefined) === "\u0000");
+    assert(String.fromCharCode(1) === "\u0001");
+    assert(String.fromCharCode(true) === "\u0001");
+    assert(String.fromCharCode(-1) === "\uffff");
+    assert(String.fromCharCode(0xffff) === "\uffff");
+    assert(String.fromCharCode(0x123ffff) === "\uffff");
+    assert(String.fromCharCode(65) === "A");
+    assert(String.fromCharCode(65, 66, 67) === "ABC");
+    assert(String.fromCharCode(228, 246, 252) === "äöü");
+
+    console.log("PASS");
+} catch (e) {
+    console.log("FAIL: " + e);
+}