LibJS: Implement most Intl.Locale.Prototype.<<keyword>> properties

The keyword accessors all have the same function body in the spec,
except for the Intl.Locale method they invoke. This generates those
properties in the same manner as RegExp.prototype.

    Intl.Locale.prototype.calendar
    Intl.Locale.prototype.caseFirst
    Intl.Locale.prototype.collation
    Intl.Locale.prototype.hourCycle
    Intl.Locale.prototype.numberingSystem

The exception is Intl.Locale.prototype.numeric, which will be defined
separately because it is a boolean value.

Userland/Libraries/LibJS/Tests/builtins/Intl/Locale/Locale.prototype.calendar.js

@@ -0,0 +1,16 @@
+describe("errors", () => {
+    test("called on non-Locale object", () => {
+        expect(() => {
+            Intl.Locale.prototype.calendar;
+        }).toThrowWithMessage(TypeError, "Not a Intl.Locale object");
+    });
+});
+
+describe("normal behavior", () => {
+    test("basic functionality", () => {
+        expect(new Intl.Locale("en").calendar).toBeUndefined();
+        expect(new Intl.Locale("en-u-ca-abc").calendar).toBe("abc");
+        expect(new Intl.Locale("en", { calendar: "abc" }).calendar).toBe("abc");
+        expect(new Intl.Locale("en-u-ca-abc", { calendar: "def" }).calendar).toBe("def");
+    });
+});

Userland/Libraries/LibJS/Tests/builtins/Intl/Locale/Locale.prototype.caseFirst.js

@@ -0,0 +1,16 @@
+describe("errors", () => {
+    test("called on non-Locale object", () => {
+        expect(() => {
+            Intl.Locale.prototype.caseFirst;
+        }).toThrowWithMessage(TypeError, "Not a Intl.Locale object");
+    });
+});
+
+describe("normal behavior", () => {
+    test("basic functionality", () => {
+        expect(new Intl.Locale("en").caseFirst).toBeUndefined();
+        expect(new Intl.Locale("en-u-kf-upper").caseFirst).toBe("upper");
+        expect(new Intl.Locale("en", { caseFirst: "lower" }).caseFirst).toBe("lower");
+        expect(new Intl.Locale("en-u-kf-upper", { caseFirst: "false" }).caseFirst).toBe("false");
+    });
+});

Userland/Libraries/LibJS/Tests/builtins/Intl/Locale/Locale.prototype.collation.js

@@ -0,0 +1,16 @@
+describe("errors", () => {
+    test("called on non-Locale object", () => {
+        expect(() => {
+            Intl.Locale.prototype.collation;
+        }).toThrowWithMessage(TypeError, "Not a Intl.Locale object");
+    });
+});
+
+describe("normal behavior", () => {
+    test("basic functionality", () => {
+        expect(new Intl.Locale("en").collation).toBeUndefined();
+        expect(new Intl.Locale("en-u-co-abc").collation).toBe("abc");
+        expect(new Intl.Locale("en", { collation: "abc" }).collation).toBe("abc");
+        expect(new Intl.Locale("en-u-co-abc", { collation: "def" }).collation).toBe("def");
+    });
+});

Userland/Libraries/LibJS/Tests/builtins/Intl/Locale/Locale.prototype.hourCycle.js

@@ -0,0 +1,16 @@
+describe("errors", () => {
+    test("called on non-Locale object", () => {
+        expect(() => {
+            Intl.Locale.prototype.hourCycle;
+        }).toThrowWithMessage(TypeError, "Not a Intl.Locale object");
+    });
+});
+
+describe("normal behavior", () => {
+    test("basic functionality", () => {
+        expect(new Intl.Locale("en").hourCycle).toBeUndefined();
+        expect(new Intl.Locale("en-u-hc-h11").hourCycle).toBe("h11");
+        expect(new Intl.Locale("en", { hourCycle: "h12" }).hourCycle).toBe("h12");
+        expect(new Intl.Locale("en-u-hc-h23", { hourCycle: "h24" }).hourCycle).toBe("h24");
+    });
+});

Userland/Libraries/LibJS/Tests/builtins/Intl/Locale/Locale.prototype.numberingSystem.js

@@ -0,0 +1,18 @@
+describe("errors", () => {
+    test("called on non-Locale object", () => {
+        expect(() => {
+            Intl.Locale.prototype.numberingSystem;
+        }).toThrowWithMessage(TypeError, "Not a Intl.Locale object");
+    });
+});
+
+describe("normal behavior", () => {
+    test("basic functionality", () => {
+        expect(new Intl.Locale("en").numberingSystem).toBeUndefined();
+        expect(new Intl.Locale("en-u-nu-abc").numberingSystem).toBe("abc");
+        expect(new Intl.Locale("en", { numberingSystem: "abc" }).numberingSystem).toBe("abc");
+        expect(new Intl.Locale("en-u-nu-abc", { numberingSystem: "def" }).numberingSystem).toBe(
+            "def"
+        );
+    });
+});