@experimental annotation doesn't work for inline functions

[gregghz]

Compiler version

3.1.3-RC2

Minimized code

https://scastie.scala-lang.org/CCUeignRSJOnYEBa8aJTWg

import scala.annotation.experimental

@experimental
inline def foo: Any = ???

@experimental
object Test {
  @experimental val x = foo
  
  @experimental
  def bar() = {
    foo
  }
  
  foo
}

Output

[E] [E3] Foo.scala:15:3
[E]      method foo is marked @experimental and therefore may only be used in an experimental scope.
[E]      L15:   foo
[E]             ^^^
[E] [E2] Foo.scala:12:5
[E]      method foo is marked @experimental and therefore may only be used in an experimental scope.
[E]      L12:     foo
[E]               ^^^
[E] [E1] Foo.scala:8:25
[E]      method foo is marked @experimental and therefore may only be used in an experimental scope.
[E]      L8:   @experimental val x = foo
[E]                                  ^^^

Expectation

I expect all foo calls to be recognized as in the experimental scope.

[gregghz]

https://github.com/lampepfl/dotty/blob/main/tests/neg-custom-args/no-experimental/experimentalInline.scala#L9:L9

I did just stumble across this test case which I think implies that this isn't a bug? If it's true that it's not a bug, I'm not sure these new experimental methods in Quotes.scala can really be used, right?

This is the one I was trying to use:
https://github.com/dotty-staging/dotty/blob/main/library/src/scala/quoted/Quotes.scala#L3645