feat(es/minifier): Drop expressions using sequential inliner

[kdy1]

Description:

I'm trying to optimize

import { upper } from "module";
let foobar = "foo";
export const foo = foobar;
const bar = "bar";
foobar += bar;
let foobarCopy = foobar;
foobar += "foo";
console.log(foobarCopy);
foobarCopy += "Unused";
function internal() {
    return upper(foobar);
}

Theoretically, a control flow graph is required for this optimization. But our sequential inliner shares some characteristics with it, so I'm investigating to check if this optimization is possible without a full control flow graph.

Related issue (if exists):

[kdy1]

This is now ready for review, but I'll wait as much as possible

[kdy1]

swc-bump:

• swc_ecma_minifier

[swc-bot]

Automated review comment generated by auto-rebase script