Add regression test

Closes scala#13732

Author: nicolasstucki

tests/pos-macros/i13732.scala

@@ -0,0 +1,6 @@
+import scala.quoted.*
+
+def generateImpl(using q: Quotes): Expr[Unit] =
+  '{ def runEffect[T]: T = ${ runEffectImpl[T] } }
+
+inline def runEffectImpl[T: Type]: Expr[T] = ???