[test] Hack: run stdlib tests first to start long-running tests earlier.

This decreases total testing time by over a minute on my old Mac Pro.
It probably has much less effect on systems with fewer cores, but shouldn't
be any worse there.

Swift SVN r22745

test/stdlib/StringReallocation.swift

@@ -1,36 +0,0 @@
-// RUN: %target-run-simple-swift | FileCheck %s
-
-// CHECK-NOT: Reallocations exceeded 30
-func testReallocation() {
-  var x = "The quick brown fox jumped over the lazy dog\n"._split(" ")
-
-  var story = "Let me tell you a story:"
-  var laps = 1000
-
-  var reallocations = 0
-  for i in 0..<laps {
-    for s in x {
-      var lastBase = story._core._baseAddress
-      story += " "
-      story += s
-      if lastBase != story._core._baseAddress {
-        ++reallocations
-        
-        // To avoid dumping a vast string here, just write the first
-        // part of the story out each time there's a reallocation.
-        var intro = story._split(":")[0]
-        println("reallocation \(reallocations), with intro \(intro)")
-        
-        if reallocations >= 30 {
-          println("Reallocations exceeded 30")
-          return
-        }
-      }
-    }
-    story += "."
-  }
-  println("total reallocations = \(reallocations)")
-}
-
-testReallocation()
-println("done!")