Fix #8845: Strip annots from proto when checking SAM

Author: nicolasstucki

compiler/src/dotty/tools/dotc/typer/Typer.scala

@@ -1170,7 +1170,7 @@ class Typer extends Namer
       if (tree.tpt.isEmpty)
         meth1.tpe.widen match {
           case mt: MethodType =>
-            pt match {
+            pt.stripAnnots match {
               case SAMType(sam)
               if !defn.isFunctionType(pt) && mt <:< sam =>
                 // SAMs of the form C[?] where C is a class cannot be conversion targets.

tests/pos/i8845.scala

@@ -0,0 +1,8 @@
+trait IntToLong:
+  def apply(v: Int) : Long
+
+inline def convert1(       f: IntToLong) = ???
+inline def convert2(inline f: IntToLong) = ???
+
+val test1 = convert1(_ * 10)
+val test2 = convert2(_ * 10)