add test for macro mixing

Author: johnduffell

tests/pos-macros/i16630.scala

@@ -0,0 +1,6 @@
+import scala.language.experimental.macros
+
+trait TraitWithTypeParam[A] {
+  protected inline def foo: Option[A] = ${ ??? }
+  protected def foo: Option[A] = macro ???
+}