child_process: define EACCES as a runtime error

Access permission on the target child is currently thrown
as an exception. Bring this under the runtime error definition,
much like ENOENT and friends.

PR-URL: #19294
Fixes: nodejs/help#990
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Prince John Wesley <princejohnwesley@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

lib/internal/child_process.js

@@ -33,6 +33,7 @@ const { isUint8Array } = require('internal/util/types');
 const spawn_sync = process.binding('spawn_sync');
 
 const {
+  UV_EACCES,
   UV_EAGAIN,
   UV_EINVAL,
   UV_EMFILE,
@@ -315,7 +316,8 @@ ChildProcess.prototype.spawn = function(options) {
   var err = this._handle.spawn(options);
 
   // Run-time errors should emit an error, not throw an exception.
-  if (err === UV_EAGAIN ||
+  if (err === UV_EACCES ||
+      err === UV_EAGAIN ||
       err === UV_EMFILE ||
       err === UV_ENFILE ||
       err === UV_ENOENT) {