Remove trace macro. Too unstable.

Also, it was duplicated in scala/scala.
This one seems to have been unused.

Author: adriaanm

src/main/scala/scala/tools/partest/package.scala

@@ -184,55 +184,6 @@ package object partest {
     vlog(allPropertiesString)
   }
 
-  import scala.language.experimental.macros
-
-  /**
-   * `trace("".isEmpty)` will return `true` and as a side effect print the following to standard out.
-   * {{{
-   *   trace> "".isEmpty
-   *   res: Boolean = true
-   *
-   * }}}
-   *
-   * An alternative to [[scala.tools.partest.ReplTest]] that avoids the inconvenience of embedding
-   * test code in a string.
-   */
-  def trace[A](a: A) = macro traceImpl[A]
-
-  import scala.reflect.macros.BlackboxContext
-  def traceImpl[A: c.WeakTypeTag](c: BlackboxContext)(a: c.Expr[A]): c.Expr[A] = {
-    import c.universe._
-    import definitions._
-
-    // xeno.by: reify shouldn't be used explicitly before the final release of 2.10.0,
-    // because this impairs reflection refactorings
-    //
-    // val exprCode = c.literal(show(a.tree))
-    // val exprType = c.literal(show(a.actualType))
-    // reify {
-    //   println(s"trace> ${exprCode.splice}\nres: ${exprType.splice} = ${a.splice}\n")
-    //   a.splice
-    // }
-
-    c.Expr(Block(
-      List(Apply(
-        Select(Ident(PredefModule), TermName("println")),
-        List(Apply(
-          Select(Apply(
-            Select(Ident(ScalaPackage), TermName("StringContext")),
-            List(
-              Literal(Constant("trace> ")),
-              Literal(Constant("\\nres: ")),
-              Literal(Constant(" = ")),
-              Literal(Constant("\\n")))),
-          TermName("s")),
-          List(
-            Literal(Constant(show(a.tree))),
-            Literal(Constant(show(a.actualType))),
-            a.tree))))),
-      a.tree))
-  }
-
   def isPartestTerse   = NestUI.isTerse
   def isPartestDebug   = NestUI.isDebug
   def isPartestVerbose = NestUI.isVerbose