eta expansion may not be working correctly with multiple parameter lists

[aappddeevv]

I was expecting that eta expansion (if that's the right term) would pick-up the expansion of the first parameter list but it did not seem to:

scala> def foo(i: Int) = i.toString
def foo(i: Int): String
  | => root / scalaInstance 0s
scala>                                                                                                                        
scala> foo(10)
val res0: String = 10

scala> def processItem(f: Int => String)(v: String): Int = v.toInt
def processItem(f: Int => String)(v: String): Int

scala> processItem(foo)                                                                                                       
val res1: String => Int = Lambda$16681/862216843@14f0c2b6

scala> processItem(foo)("20")
val res2: Int = 20

scala> def lastFunc(f: String => Int): Int = f("20") 
def lastFunc(f: String => Int): Int

scala> lastFunc(processItem(foo))                                                                                             
val res3: Int = 20

scala> import scala.language.implicitConversions

scala> foo pipe processItem pipe lastFunc
1 |foo pipe processItem pipe lastFunc
  |         ^^^^^^^^^^^
  |         The syntax `<function> _` is no longer supported;
  |         you can simply leave out the trailing ` _`

It felt like this was a bug, but I do not know enough about it to determine that. It works if we do processItem(foo) pipe lastFunc.

May be related to #5288.

[OlivierBlanvillain]

Works on master (with import util.chaining.scalaUtilChainingOps)

[aappddeevv]

Thanks!