refactor(compiler): better constant hoist/stringify checks

packages/compiler-dom/__tests__/parse.spec.ts

@@ -6,7 +6,8 @@ import {
   ErrorCodes,
   ElementTypes,
   InterpolationNode,
-  AttributeNode
+  AttributeNode,
+  ConstantTypes
 } from '@vue/compiler-core'
 import { parserOptions, DOMNamespaces } from '../src/parserOptions'
 
@@ -253,7 +254,7 @@ describe('DOM parser', () => {
           type: NodeTypes.SIMPLE_EXPRESSION,
           content: `a < b`,
           isStatic: false,
-          isConstant: false,
+          constType: ConstantTypes.NOT_CONSTANT,
           loc: {
             start: { offset: 8, line: 1, column: 9 },
             end: { offset: 16, line: 1, column: 17 },

packages/compiler-dom/__tests__/transforms/stringifyStatic.spec.ts

@@ -2,7 +2,8 @@ import {
   compile,
   NodeTypes,
   CREATE_STATIC,
-  createSimpleExpression
+  createSimpleExpression,
+  ConstantTypes
 } from '../../src'
 import {
   stringifyStatic,
@@ -176,9 +177,8 @@ describe('stringify static html', () => {
                 '_imports_0_',
                 false,
                 node.loc,
-                true
+                ConstantTypes.CAN_HOIST
               )
-              exp.isRuntimeConstant = true
               node.props[0] = {
                 type: NodeTypes.DIRECTIVE,
                 name: 'bind',