SI-7033 Be symful when creating factory methods.

Implicit class factory methods were synthesizing the
reference to the class as `Ident(classDef.name)`, which
was unhygienic in case of `implicit class X[X]`.

To use symbols without causing a cycle, I switched from
`REF(symbol)` to `Ident(symbol)`. The former calls into:

    at scala.reflect.internal.TreeGen.mkAttributedSelect(TreeGen.scala:184)
    at scala.reflect.internal.TreeGen.mkAttributedRef(TreeGen.scala:124)
    at scala.reflect.internal.TreeGen.mkAttributedRef(TreeGen.scala:130)
    at scala.tools.nsc.ast.TreeDSL$CODE$.REF(TreeDSL.scala:307)

which forces the info of enclosing module and forms a cycle.

1 files changed, 15 insertions, 0 deletions

diff --git a/test/files/pos/t7033.scala b/test/files/pos/t7033.scala
new file mode 100644
index 0000000000..a4d256673b
--- /dev/null
+++ b/test/files/pos/t7033.scala
@@ -0,0 +1,15 @@
+import language.higherKinds
+object Wrap {
+  implicit class X[X](val a: X)
+
+  X[Int](0)
+}
+
+class Wrap {
+  implicit class Y[Y](val a: Y)
+  Y[Int](0)
+  implicit class Z[Z[_]](val a: Z[Wrap.this.Z[Z]])
+  Z[List](List(new Z[List](null)))
+}
+
+case class X[X](val a: X)