SI-9349 Fix use of patmat binder as prefix for new x.Inner

When substituting in references to the synthetic values
representing pattern binders, we were replacing:

    Select(Ident(o).setType(o.type), TypeName("Inner"))

with:

    Select(Ident(x2).setType(typeOf[Outer]), TypeName("Inner"))

The post transform in uncurry would then run:

     else if (tree.isType)
        TypeTree(tree.tpe) setPos tree.pos

Which would loses track of the outer term `o` and crashes the
compiler in ExplicitOuter.

This commit generates stable references to the binders.
I made this change in the substitutions for all `TreeMakers`,
however only one of seems like it triggers a crash in the
test variations I tried.

Here's how the trees for the first pattern in the test case
change after this patch:

```
@@ -1,30 +1,30 @@
 [[syntax trees at end of                    patmat]] // test.scala
 package <empty>{<empty>.type} {
   object Test extends scala.AnyRef {
     def <init>(): Test.type = {
       Test.super{Test.type}.<init>{()Object}(){Object};
       (){Unit}
     }{Unit};
     def main(args: Array[String]): Unit = {
       val o1: Outer = Outer.apply{(i: Int)Outer}(5{Int(5)}){Outer};
       {
         case <synthetic> val x1: Outer = o1{Outer};
         case5(){
           if (x1.ne{(x$1: AnyRef)Boolean}(null{Null(null)}){Boolean})
             matchEnd4{(x: Unit)Unit}({
-              val i: Outer#Inner = new x1.Inner{Outer#Inner}{()Outer#Inner}(){Outer#Inner};
+              val i: x1.Inner = new x1.Inner{x1.Inner}{()x1.Inner}(){x1.Inner};
               (){Unit}
             }{Unit}){Unit}
           else
             case6{()Unit}(){Unit}{Unit}
         }{Unit};
         case6(){
           matchEnd4{(x: Unit)Unit}(throw new MatchError{MatchError}{(obj: Any)MatchError}(x1{Outer}){MatchError}{Nothing}){Unit}
         }{Unit};
         matchEnd4(x: Unit){
           x{Unit}
         }{Unit}
       }{Unit}
     }{Unit}
   }
```

1 files changed, 1 insertions, 0 deletions

diff --git a/test/files/run/t9349/data.scala b/test/files/run/t9349/data.scala
new file mode 100644
index 0000000000..f88a6cfaeb
--- /dev/null
+++ b/test/files/run/t9349/data.scala
@@ -0,0 +1 @@
+case class Outer(i: Int) { class Inner }