[runtime] Cleanup native methods creation in js/proxy.js.

This CL replaces usages of utils.InstallFunctions and utils.InstallGetter()
with the DEFINE_METHOD* macros that ensure that the native function is
created in proper form from the beginning. Thus the function will not
require further reconfiguring like adding a computed name or removing of
'prototype' property.

This CL is one of a series of cleanup CL which are the preliminary steps for
improving function closures creation.

Bug: v8:6459
Change-Id: Ic78aa448ffee2cd6edf2d18fd303a34a065ff95a
Reviewed-on: https://chromium-review.googlesource.com/548176
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46298}

src/js/proxy.js

@@ -15,16 +15,13 @@ var GlobalProxy = global.Proxy;
 
 //----------------------------------------------------------------------------
 
-function ProxyCreateRevocable(target, handler) {
+//Set up non-enumerable properties of the Proxy object.
+DEFINE_METHOD(
+  GlobalProxy,
+  revocable(target, handler) {
     var p = new GlobalProxy(target, handler);
     return {proxy: p, revoke: () => %JSProxyRevoke(p)};
-}
-
-//-------------------------------------------------------------------
-
-//Set up non-enumerable properties of the Proxy object.
-utils.InstallFunctions(GlobalProxy, DONT_ENUM, [
-  "revocable", ProxyCreateRevocable
-]);
+  }
+);
 
 })