Fix atomic_shared_ptr tests

Summary: D9312236 (https://github.com/facebook/folly/commit/bc16b096b1f6659e29379a650998bbfcf0c03eca) made these tests conditional on using libstdc++, but the header that defines the macro is not included prior to the `#ifdef`, so the tests (and benchmarks) are disabled unconditionally.

Reviewed By: yfeldblum

Differential Revision: D23469536

fbshipit-source-id: 2ab0b2d28748419d88e946eff9b09b98d361dedb

folly/concurrency/test/AtomicSharedPtrPerformance.cpp

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#include <folly/portability/Config.h>
+
 // AtomicSharedPtr-detail.h only works with libstdc++, so skip these tests for
 // other vendors
 #ifdef FOLLY_USE_LIBSTDCPP
@@ -39,6 +41,7 @@ using std::make_shared;
 using std::memory_order;
 using std::memory_order_acq_rel;
 using std::memory_order_acquire;
+using std::memory_order_consume;
 using std::memory_order_relaxed;
 using std::memory_order_release;
 using std::memory_order_seq_cst;
@@ -64,6 +67,8 @@ static const char* memoryOrder(memory_order order) {
       return "relaxed";
     case memory_order_acquire:
       return "acquire";
+    case memory_order_consume:
+      return "consume";
     case memory_order_release:
       return "release";
     case memory_order_acq_rel:

folly/concurrency/test/AtomicSharedPtrTest.cpp

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#include <folly/portability/Config.h>
+
 // AtomicSharedPtr-detail.h only works with libstdc++, so skip these tests for
 // other vendors
 #ifdef FOLLY_USE_LIBSTDCPP

folly/concurrency/test/CoreCachedSharedPtrTest.cpp

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#include <folly/portability/Config.h>
+
 // AtomicSharedPtr-detail.h only works with libstdc++, so skip these tests for
 // other vendors
 #ifdef FOLLY_USE_LIBSTDCPP