fix(Input/Textarea): add v-model modifiers (#856)

src/runtime/utils/index.ts

@@ -56,4 +56,13 @@ export function getSlotsChildren (slots: any) {
   return children
 }
 
+/**
+ * "123-foo" will be parsed to 123
+ * This is used for the .number modifier in v-model
+ */
+export function looseToNumber (val: any): any {
+  const n = parseFloat(val)
+  return isNaN(n) ? val : n
+}
+
 export * from './lodash'