Typer regression for macros using class with default parameters list under separete compilation units

[WojciechMazur]

Based on the OpenCB failure in greenfossil/data-mapping - build logs

Compiler version

3.9.0-RC4
Bisect points to 80517e5 / #26063

Last good release: 3.9.0-RC1-bin-20260515-ed18d94-NIGHTLY
First bad release: 3.9.0-RC1-bin-20260517-80517e5-NIGHTLY

Minimized code

// macro.scala 

trait Binder[T]

object Binder:
  def foo(s: String): Binder[Int] = new Binder[Int] {}
  val foo: Binder[Int] = foo("x")

// Named `binder =` skips the defaulted `name` parameter.
case class Box[A](tpe: String, name: String = "", binder: Binder[A] = null)

object Mapping:
  inline def localDate: Box[Int] =
    Box("LocalDate", binder = Binder.foo)

// test.test.scala - requires separate compilation unit
//> using file macro.scala

@main def Test = Mapping.localDate

Requires seperate compilation unit, reproductible the easiest under scala-cli --test target scope

scala compile --test test.test.scala -S 3.nightly  

Output

Checked https://repo1.maven.org/maven2/org/scala-lang/scala3-library_3/maven-metadata.xml
-- [E007] Type Mismatch Error: /Users/wmazur/projects/scala/community-build3/test.test.scala:3:25 
 3 |@main def Test = Mapping.localDate
   |                 ^^^^^^^^^^^^^^^^^
   |                 Found:    (Binder.foo : Binder[Int])
   |                 Required: <overloaded Binder.foo>
   |----------------------------------------------------------------------------
   |Inline stack trace
   |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
   |This location contains code that was inlined from test-macro.scala:12
12 |    Box("LocalDate", binder = Binder.foo)
   |                              ^^^^^^^^^^
    ----------------------------------------------------------------------------
   |
   | longer explanation available when compiling with `-explain`
1 error found
Compilation failed

Expectation

[Gedochao]

cc @nox213 @SolalPirelli

[nox213]

I will take a look