ScalaJS TypeError when calling toString under explicit nulls and unsafeNulls

[olhotak]

Compiler version

Scala 3.10.1-RC1-bin-20260905-8163579-NIGHTLY

Minimized code

//> using scala 3.nightly
//> using platform js
//> using options -Yexplicit-nulls -language:unsafeNulls

// Run with: scala-cli run --server=false --js-version 1.22.0 foo.scala
@main def main(): Unit = println(scala.scalajs.js.Symbol("s").toString())

Output

/tmp/main3109398371773400863.js:1147
      throw e;
      ^

TypeError: Cannot convert a Symbol value to a string
    at $c_Lfoo$package$.main__V (/tmp/main3109398371773400863.js:1091:15)
    at $s_Lmain__main__AT__V (/tmp/main3109398371773400863.js:1141:24)
    at Object.<anonymous> (/tmp/main3109398371773400863.js:2079:1)
    at Object.<anonymous> (/tmp/main3109398371773400863.js:2080:4)
    at Module._compile (node:internal/modules/cjs/loader:1529:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1613:10)
    at Module.load (node:internal/modules/cjs/loader:1275:32)
    at Module._load (node:internal/modules/cjs/loader:1096:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:164:12)
    at node:internal/main/run_main_module:28:49

Node.js v20.19.2

Expectation

Same behaviour as without unsafeNulls, where it runs without crashing and prints:

Symbol(s)

[olhotak]

Related to #26771

[sjrd]

I opened scala-js/scala-js#5407 as well.