Add include for 'test_macros.h' to all the tests that were missing them. Thanks to Zoe for the (big, but simple) patch. NFC intended.

llvm-svn: 362252
diff --git a/libcxx/test/std/strings/basic.string/string.require/contiguous.pass.cpp b/libcxx/test/std/strings/basic.string/string.require/contiguous.pass.cpp
index be090c9..af34fc9 100644
--- a/libcxx/test/std/strings/basic.string/string.require/contiguous.pass.cpp
+++ b/libcxx/test/std/strings/basic.string/string.require/contiguous.pass.cpp
@@ -13,6 +13,7 @@
 #include <string>
 #include <cassert>
 
+#include "test_macros.h"
 #include "test_allocator.h"
 #include "min_allocator.h"