feat(compiler-core): more hoisting optimizations (#276)

packages/compiler-core/src/ast.ts

@@ -172,6 +172,7 @@ export interface SimpleExpressionNode extends Node {
   type: NodeTypes.SIMPLE_EXPRESSION
   content: string
   isStatic: boolean
+  isConstant: boolean
   // an expression parsed as the params of a function will track
   // the identifiers declared inside the function body.
   identifiers?: string[]
@@ -501,11 +502,13 @@ export function createObjectProperty(
 export function createSimpleExpression(
   content: SimpleExpressionNode['content'],
   isStatic: SimpleExpressionNode['isStatic'],
-  loc: SourceLocation = locStub
+  loc: SourceLocation = locStub,
+  isConstant: boolean = false
 ): SimpleExpressionNode {
   return {
     type: NodeTypes.SIMPLE_EXPRESSION,
     loc,
+    isConstant,
     content,
     isStatic
   }