test for silent annotation with macros

test/files/neg/silentWarningsMacros.check

@@ -0,0 +1,12 @@
+Test_2.scala:10: warning: a pure expression does nothing in statement position; multiline expressions might require enclosing parentheses
+    1 // warn
+    ^
+Test_2.scala:19: warning: a pure expression does nothing in statement position; multiline expressions might require enclosing parentheses
+    1 // warn
+    ^
+Test_2.scala:28: warning: a pure expression does nothing in statement position; multiline expressions might require enclosing parentheses
+    1 // warn
+    ^
+error: No warnings can be incurred under -Werror.
+three warnings found
+one error found

test/files/neg/silentWarningsMacros/Macro_1.scala

@@ -0,0 +1,8 @@
+import scala.reflect.macros.blackbox.Context
+
+object Macro {
+  def discard(c: Context)(expr: c.Expr[Any]): c.Tree = {
+    import c.universe._
+    q"()"
+  }
+}

test/files/neg/silentWarningsMacros/Test_2.scala

@@ -0,0 +1,35 @@
+// scalac: -Werror
+
+import language.experimental.macros
+import scala.annotation.silent
+
+object Test {
+  def discard(expr: Any): Unit = macro Macro.discard
+
+  def t1a = discard {
+    1 // warn
+    2
+  }
+  def t1b = discard {
+    1: @silent
+    2
+  }
+
+  def t2a = discard {
+    1 // warn
+    2
+  }
+  @silent def t2b = discard {
+    1
+    2
+  }
+
+  def t3a = discard {
+    1 // warn
+    2
+  }
+  def t3b = discard {
+    1 // warn
+    2
+  }: @silent
+}