Don't mark mixed in methods as bridges.

Sometime during the signature-related chaos before 2.9.1,
genjvm was modified to pin ACC_BRIDGE onto mixed-in methods.
This isn't necessary to suppress the signature (which has
already happened at that point) and has deleterious effects
since many tools ignore bridge methods.  Review by @odersky.

Author: paulp

src/compiler/scala/tools/nsc/backend/jvm/GenJVM.scala

@@ -1901,7 +1901,7 @@ abstract class GenJVM extends SubComponent with GenJVMUtil with GenAndroid with
       if (sym.isInterface) ACC_INTERFACE else 0,
       if (finalFlag) ACC_FINAL else 0,
       if (sym.isStaticMember) ACC_STATIC else 0,
-      if (sym.isBridge || sym.hasFlag(Flags.MIXEDIN) && sym.isMethod) ACC_BRIDGE else 0,
+      if (sym.isBridge) ACC_BRIDGE else 0,
       if (sym.isClass && !sym.isInterface) ACC_SUPER else 0,
       if (sym.isVarargsMethod) ACC_VARARGS else 0
     )

test/files/run/mixin-bridge-methods.scala

@@ -0,0 +1,14 @@
+trait Foo {
+  def getFoo() = "foo"
+}
+
+class Sub extends Foo {
+  def getBar() = "bar"
+}
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val ms = classOf[Sub].getDeclaredMethods
+    assert(ms forall (x => !x.isBridge), ms mkString " ")
+  }
+}