Import cycles through star exports

[bojavou]

Import cycles have some interaction with star exports. Where one star export finds a cycle and another finds a binding, the binding should override and resolve successfully.

It was pointed out to me that typically a cycle will cause a crash elsewhere, when InitializeEnvironment detects it. But that shouldn't happen in the case where a star export is in the middle of the cycle. There is inconsistency in implementations on this point. I wonder if it should be in the test suite.

There are eshost outputs below, plus browser demos. The browser demos log/error to the console.

---

Cycle on both sides, wrapped in named exports.

https://bojavou.github.io/star-export-cycle/biname/

https://github.com/bojavou/star-export-cycle/tree/main/biname

// entry.mjs
import { value } from './left.mjs'
print(value)

// left.mjs
export { value } from './middle.mjs'

// middle.mjs
export * from './left.mjs'
export * from './right.mjs'
export * from './bind.mjs'

// right.mjs
export { value } from './middle.mjs'

// bind.mjs
export const value = 'bind'

$ eshost entry.mjs
#### engine262
bind

#### JavaScriptCore
bind

#### SpiderMonkey
bind

#### V8

SyntaxError: Detected cycle while resolving name 'value' in './middle.mjs'

#### XS

SyntaxError: (host): import value ambiguous

---

Cycle on one side, wrapped in named exports.

https://bojavou.github.io/star-export-cycle/uniname/

https://github.com/bojavou/star-export-cycle/tree/main/uniname

// entry.mjs
import { value } from './left.mjs'
print(value)

// left.mjs
export { value } from './middle.mjs'

// middle.mjs
export * from './right.mjs'
export * from './bind.mjs'

// right.mjs
export { value } from './middle.mjs'

// bind.mjs
export const value = 'bind'

$ eshost entry.mjs
#### engine262
bind

#### JavaScriptCore
bind

#### SpiderMonkey
bind

#### V8
bind

#### XS

SyntaxError: (host): import value ambiguous

---

Cycle on both sides, wrapped in star exports.

https://bojavou.github.io/star-export-cycle/bistar/

https://github.com/bojavou/star-export-cycle/tree/main/bistar

// entry.mjs
import { value } from './left.mjs'
print(value)

// left.mjs
export * from './middle.mjs'

// middle.mjs
export * from './left.mjs'
export * from './right.mjs'
export * from './bind.mjs'

// right.mjs
export * from './middle.mjs'

// bind.mjs
export const value = 'bind'

$ eshost entry.mjs
#### engine262
bind

#### JavaScriptCore
bind

#### SpiderMonkey
bind

#### V8
bind

#### XS
bind

---

Cycle on one side, wrapped in star exports.

This behaves identically to bistar.

https://bojavou.github.io/star-export-cycle/unistar/

https://github.com/bojavou/star-export-cycle/tree/main/unistar

// entry.mjs
import { value } from './left.mjs'
print(value)

// left.mjs
export * from './middle.mjs'

// middle.mjs
export * from './right.mjs'
export * from './bind.mjs'

// right.mjs
export * from './middle.mjs'

// bind.mjs
export const value = 'bind'

$ eshost entry.mjs
#### engine262
bind

#### JavaScriptCore
bind

#### SpiderMonkey
bind

#### V8
bind

#### XS
bind