fix: preserve top-level when running terser for IIFE

[sapphi-red]

When globalName: 'globalFoo' is set and the output format is iife, the output for the following input was not correct.
The variable globalFoo is not declared in the output.

// input
export default 'foo'

// output (formatted)
'use strict'
;(() => {
  var e = Object.defineProperty,
    t = Object.getOwnPropertyDescriptor,
    r = Object.getOwnPropertyNames,
    o = Object.prototype.hasOwnProperty,
    a = {}
  ;((t, r) => {
    for (var o in r) e(t, o, { get: r[o], enumerable: !0 })
  })(a, { default: () => n })
  var f,
    n = 'foo'
  ;(f = a),
    ((a, f, n, c) => {
      if ((f && 'object' == typeof f) || 'function' == typeof f)
        for (let l of r(f))
          o.call(a, l) ||
            l === n ||
            e(a, l, {
              get: () => f[l],
              enumerable: !(c = t(f, l)) || c.enumerable,
            })
    })(e({}, '__esModule', { value: !0 }), f)
})()

This PR fixes this issue by avoid setting toplevel: true when the format is iife and globalName option is set.

// new output (formatted)
'use strict'
var globalFoo = (() => {
  var e = Object.defineProperty,
    r = Object.getOwnPropertyDescriptor,
    t = Object.getOwnPropertyNames,
    o = Object.prototype.hasOwnProperty,
    a = {}
  ;((r, t) => {
    for (var o in t) e(r, o, { get: t[o], enumerable: !0 })
  })(a, { default: () => l })
  var n,
    l = 'foo'
  return (
    (n = a),
    ((a, n, l, f) => {
      if ((n && 'object' == typeof n) || 'function' == typeof n)
        for (let u of t(n))
          o.call(a, u) ||
            u === l ||
            e(a, u, {
              get: () => n[u],
              enumerable: !(f = r(n, u)) || f.enumerable,
            })
      return a
    })(e({}, '__esModule', { value: !0 }), n)
  )
})()

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Name	Status	Preview	Comments	Updated (UTC)
tsup	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jun 16, 2023 6:33am

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🎉 This PR is included in version 7.0.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

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