avoid using public class fields in js

Author: walkingeyerobot

src/library.js

@@ -2282,8 +2282,10 @@ addToLibrary({
   },
 
   $HandleAllocator: class {
-    allocated = [undefined];
-    freelist = [];
+    constructor() {
+      this.allocated = [undefined];
+      this.freelist = [];
+    }
     get(id) {
 #if ASSERTIONS
       assert(this.allocated[id] !== undefined, `invalid handle: ${id}`);

src/library_bootstrap.js

@@ -16,8 +16,8 @@ addToLibrary({
   $callRuntimeCallbacks: () => {},
 
   $ExitStatus: class {
-    name = 'ExitStatus';
     constructor(status) {
+      this.name = 'ExitStatus';
       this.message = `Program terminated with exit(${status})`;
       this.status = status;
     }

src/library_wasi.js

@@ -7,8 +7,8 @@
 var WasiLibrary = {
 #if !MINIMAL_RUNTIME
   $ExitStatus: class {
-    name = 'ExitStatus';
     constructor(status) {
+      this.name = 'ExitStatus';
       this.message = `Program terminated with exit(${status})`;
       this.status = status;
     }