tweak parser warning output

Author: yyx990803

lib/template-compiler.js

@@ -64,10 +64,10 @@ module.exports = function (html) {
   }, defaultCompileOptions))
   var code
   if (compiled.errors.length) {
-    var self = this
-    compiled.errors.forEach(function (err) {
-      self.emitError('\n  Vue template syntax error:\n\n  ' + err + '\n')
-    })
+    this.emitError(
+      `\n  Error compiling template:\n${pad(html)}\n` +
+      compiled.errors.map(e => `  - ${e}`).join('\n') + '\n'
+    )
     code = 'module.exports={render:function(){},staticRenderFns:[]}'
   } else {
     var bubleOptions = vueOptions.buble
@@ -104,3 +104,7 @@ function toFunction (code) {
     indent_size: 2 // eslint-disable-line camelcase
   }) + '}'
 }
+
+function pad (html) {
+  return html.split(/\r?\n/).map(line => `  ${line}`).join('\n')
+}