Added ensureAccessible to reflection library.

This method comes up with some frequency and there are a lot
of ways to write it either unsafely (failing to catch a likely
exception) or with inadequate generality (as was done in the
pre-existing version of this method in ScalaRunTime) so I
thought it warranted a place in the standard library.

Author: paulp

src/library/scala/reflect/package.scala

@@ -1,5 +1,7 @@
 package scala
 
+import java.lang.reflect.{ AccessibleObject => jAccessibleObject }
+
 package object reflect {
 
   // in the new scheme of things ClassManifests are aliased to ClassTags
@@ -42,6 +44,18 @@ package object reflect {
 
   def classTag[T](implicit ctag: ClassTag[T]) = ctag
 
+  /** Make a java reflection object accessible, if it is not already
+   *  and it is possible to do so. If a SecurityException is thrown in the
+   *  attempt, it is caught and discarded.
+   */
+  def ensureAccessible[T <: jAccessibleObject](m: T): T = {
+    if (!m.isAccessible) {
+      try m setAccessible true
+      catch { case _: SecurityException => } // does nothing
+    }
+    m
+  }
+
   // anchor for the class tag materialization macro emitted during tag materialization in Implicits.scala
   // implementation is hardwired into `scala.reflect.reify.Taggers`
   // using the mechanism implemented in `scala.tools.reflect.FastTrack`

src/library/scala/runtime/ScalaRunTime.scala

@@ -158,13 +158,7 @@ object ScalaRunTime {
 
   // Java bug: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4071957
   // More background at ticket #2318.
-  def ensureAccessible(m: JMethod): JMethod = {
-    if (!m.isAccessible) {
-      try m setAccessible true
-      catch { case _: SecurityException => () }
-    }
-    m
-  }
+  def ensureAccessible(m: JMethod): JMethod = scala.reflect.ensureAccessible(m)
 
   def checkInitialized[T <: AnyRef](x: T): T =
     if (x == null) throw new UninitializedError else x