improve(tree-shaking): remove dynamic and require dep after tree-shaking

[stormslowly]

problem

// ==> index.ts <==
import { foo } from "./foo";

console.log(foo());

// ==> foo/foo.js <==
console.log('foo/foo');

// ==> foo/index.js <==
export function foo() {
  console.log(1);
}

export function bar() {
  return require("./foo.js");
}

after tree-shaking, function bar is removed, but there is still a edge to foo/foo.js, so it will be kept in the module graph.

expect the foo/foo.js removed from the module graph

solution

after tree-shaking , analyze the shaken ast, to found if the dynamic and cjs-require are still in use.

[stormslowly]

@goo-yyh 增加一个 foo 在环上的 case，