feat(ujs) show errors when component can't be loaded

Author: rmosolgo

react_ujs/src/getConstructor/fromRequireContextWithGlobalFallback.js

@@ -11,9 +11,14 @@ module.exports = function(reqctx) {
     try {
       // `require` will raise an error if this className isn't found:
       component = fromCtx(className)
-    } catch (err) {
+    } catch (firstErr) {
       // fallback to global:
-      component = fromGlobal(className)
+      try {
+        component = fromGlobal(className)
+      } catch (secondErr) {
+        console.error(firstErr)
+        console.error(secondErr)
+      }
     }
     return component
   }