Add a convenience method to Symbol to "resugar" fields

val and var members of classes are split into getter/setter and field
symbols. However, we can't call `defString` on any of these and see
what existed in source code.

Example:

```
scala> class X { protected var x: Int = 0 }
defined class X

scala> val xField = typeOf[X].member(TermName("x "))
xField: $r.intp.global.Symbol = variable x

scala> xField.defString
res10: String = private[this] var x: Int

scala> xField.getterIn(xField.owner).defString
res11: String = protected def x: Int

scala> xField.setterIn(xField.owner).defString
res12: String = protected def x_=(x$1: Int): Unit
```

This commit introduces a new method on `Symbol` that pieces together
the information from these symbols to create an artificial symbol
that has the `defString` we're after:

```
scala> xField.sugaredSymbolOrSelf.defString
res14: String = protected var x: Int
```

0 files changed, 0 insertions, 0 deletions