[libcxx] [test] Replace _LIBCPP_STD_VER with TEST_STD_VER.

This replaces every occurrence of _LIBCPP_STD_VER in the tests with
TEST_STD_VER. Additionally, for every affected
file, #include "test_macros.h" is being added explicitly if it wasn't
already there.

https://reviews.llvm.org/D26294

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@286007 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/utilities/tuple/tuple.tuple/tuple.creation/tie.pass.cpp

@@ -20,6 +20,8 @@
 #include <string>
 #include <cassert>
 
+#include "test_macros.h"
+
 int main()
 {
     {
@@ -29,7 +31,7 @@ int main()
         assert(i == 42);
         assert(s == "C++");
     }
-#if _LIBCPP_STD_VER > 11
+#if TEST_STD_VER > 11
     {
         static constexpr int i = 42;
         static constexpr double f = 1.1;