[JS IR] Make Char a value class (again)

#KT-35100 Fixed

js/js.translator/testData/box/char/charInExternalDecl.js

@@ -0,0 +1,69 @@
+function actualTypeOfChar(x) {
+    return typeof x;
+}
+
+function actualTypeOfMaybeChar(x) {
+    return actualTypeOfChar(x);
+}
+
+function getSomeChar() {
+    return 'a'.charCodeAt(0);
+}
+
+function getMaybeChar() {
+    return getSomeChar();
+}
+
+function getCharNull() {
+    return null;
+}
+
+var charVal = getSomeChar();
+var maybeCharVal = getMaybeChar();
+var charNullVal = getCharNull();
+
+var charVar = getSomeChar();
+var maybeCharVar = null;
+
+function A(c) {
+    this.c = c;
+    this._baz = 'q'.charCodeAt(0);
+    this._nullableBaz = null;
+}
+
+A.prototype.foo = function () {
+    return this.c;
+};
+
+A.prototype.maybeFoo = A.prototype.foo;
+A.prototype.fooNull = getCharNull;
+
+A.prototype.actualTypeOfChar = actualTypeOfChar
+A.prototype.actualTypeOfMaybeChar = actualTypeOfMaybeChar
+
+Object.defineProperty(A.prototype, 'bar', {
+    configurable: true,
+    get: A.prototype.foo
+});
+
+Object.defineProperty(A.prototype, 'maybeBar', {
+    configurable: true,
+    get: A.prototype.maybeFoo
+});
+
+Object.defineProperty(A.prototype, 'barNull', {
+    configurable: true,
+    get: A.prototype.fooNull
+});
+
+Object.defineProperty(A.prototype, 'baz', {
+    configurable: true,
+    get: function () { return this._baz; },
+    set: function (v) { this._baz = v; }
+});
+
+Object.defineProperty(A.prototype, 'maybeBaz', {
+    configurable: true,
+    get: function () { return this._nullableBaz; },
+    set: function (v) { this._nullableBaz = v; }
+});