Fix: block unnecessary input event on input tag placeholder in IE (vuejs#8140)

Author: donggyu04

src/platforms/web/runtime/modules/attrs.js

@@ -97,7 +97,7 @@ function baseSetAttr (el, key, value) {
     /* istanbul ignore if */
     if (
       isIE && !isIE9 &&
-      el.tagName === 'TEXTAREA' &&
+      (el.tagName === 'TEXTAREA' || el.tagName === 'INPUT') &&
       key === 'placeholder' && !el.__ieph
     ) {
       const blocker = e => {