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

#KT-35100 Fixed

js/js.translator/testData/box/char/topLevelCallables.kt

@@ -1,16 +1,15 @@
 // SKIP_MINIFICATION
 
-// Exported declaration uses non-exportable return type: Char
-// IGNORE_BACKEND: JS_IR
-// IGNORE_BACKEND: JS_IR_ES6
-
-@JsName("foo")
+@JsExport
 fun foo(): Char = '1'
 
+@JsExport
 val p1: Char = '2'
 
+@JsExport
 var p2: Char = '3'
 
+@JsExport
 var p3: Char = '4'
     get() = field + 1
     set(value) {