Bringing a bit of order to symbol substitution.

Painstakingly winnowed out the most frequently duplicated code sequences
related to symbol cloning and substitution. Created canonical methods to
perform these actions and documented them. Key methods include:

  def createFromClonedSymbols[T](syms: List[Symbol], tpe: Type)(creator: (List[Symbol], Type) => T): T
  def deriveSymbols(syms: List[Symbol], symFn: Symbol => Symbol): List[Symbol]
  def deriveType(syms: List[Symbol], symFn: Symbol => Symbol)(tpe: Type): Type

Many example usages enclosed with commit.

I did lots of timing tests, I find no material difference before and
after. Actually I won by four seconds in this incarnation:

  Before - Total time: 7 minutes 55 seconds
   After - Total time: 7 minutes 51 seconds

Review by moors.

1 files changed, 5 insertions, 4 deletions

diff --git a/src/compiler/scala/reflect/runtime/Loaders.scala b/src/compiler/scala/reflect/runtime/Loaders.scala
index eaf3c82d5a..35b3a16dc2 100644
--- a/src/compiler/scala/reflect/runtime/Loaders.scala
+++ b/src/compiler/scala/reflect/runtime/Loaders.scala
@@ -71,12 +71,13 @@ trait Loaders { self: SymbolTable =>
     (clazz, module)
   }
 
-  protected def initClassModule(clazz: Symbol, module: Symbol, completer: LazyType) = {
-    clazz.setInfo(completer)
-    module.setInfo(completer)
-    module.moduleClass.setInfo(completer)
+  protected def setAllInfos(clazz: Symbol, module: Symbol, info: Type) = {
+    List(clazz, module, module.moduleClass) foreach (_ setInfo info)
   }
 
+  protected def initClassModule(clazz: Symbol, module: Symbol, completer: LazyType) =
+    setAllInfos(clazz, module, completer)
+
   /** The type completer for packages.
    */
   class LazyPackageType extends LazyType {