[test] renaming test/1_stdlib to just test/stdlib

test/stdlib/StringReallocation.swift

@@ -0,0 +1,37 @@
+// RUN: %target-run-simple-swift | %FileCheck %s
+// REQUIRES: executable_test
+
+// CHECK-NOT: Reallocations exceeded 30
+func testReallocation() {
+  var x = "The quick brown fox jumped over the lazy dog\n"._split(separator: " ")
+
+  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 += 1
+        
+        // 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(separator: ":")[0]
+        print("reallocation \(reallocations), with intro \(intro)")
+        
+        if reallocations >= 30 {
+          print("Reallocations exceeded 30")
+          return
+        }
+      }
+    }
+    story += "."
+  }
+  print("total reallocations = \(reallocations)")
+}
+
+testReallocation()
+print("done!")