Fix #10900: Avoid loop for F-bounds in checkCanEqual

Author: liufengyun

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

@@ -929,6 +929,8 @@ trait Implicits:
           apply(t.widen)
         case t: RefinedType =>
           apply(t.parent)
+        case t: LazyRef =>
+          t
         case _ =>
           if (variance > 0) mapOver(t) else t
       }

tests/pos/i10900.scala

@@ -0,0 +1,3 @@
+import scala.collection.IterableOps
+def foo[CC[A] <: IterableOps[A, CC, CC[A]], A](collection: CC[A]) =
+  collection == collection