Add missing gflags #include in tests (#1051)

Summary:
Some tests fail to compile because gflags.h is not included:

    .../folly/test/FormatOtherTest.cpp: In function 'int main(int, char**)':
    .../folly/test/FormatOtherTest.cpp:113:3: error: 'gflags' has not been declared
       gflags::ParseCommandLineFlags(&argc, &argv, true);
       ^~~~~~

The tests compile without issue on Travis CI without this patch, but I
don't see how that's possible.

Include gflags.h explicitly to fix the compilation of these tests.
Pull Request resolved: https://github.com/facebook/folly/pull/1051

Reviewed By: aary

Differential Revision: D14400709

Pulled By: yfeldblum

fbshipit-source-id: 73999a940f45511373d3922ea8eb782a27af0008

folly/concurrency/test/ConcurrentHashMapTest.cpp

@@ -21,6 +21,7 @@
 #include <thread>
 
 #include <folly/hash/Hash.h>
+#include <folly/portability/GFlags.h>
 #include <folly/portability/GTest.h>
 #include <folly/test/DeterministicSchedule.h>
 

folly/concurrency/test/DynamicBoundedQueueTest.cpp

@@ -17,6 +17,7 @@
 #include <folly/concurrency/DynamicBoundedQueue.h>
 #include <folly/MPMCQueue.h>
 #include <folly/ProducerConsumerQueue.h>
+#include <folly/portability/GFlags.h>
 #include <folly/portability/GTest.h>
 
 #include <glog/logging.h>

folly/concurrency/test/UnboundedQueueTest.cpp

@@ -17,6 +17,7 @@
 #include <folly/concurrency/UnboundedQueue.h>
 #include <folly/MPMCQueue.h>
 #include <folly/ProducerConsumerQueue.h>
+#include <folly/portability/GFlags.h>
 #include <folly/portability/GTest.h>
 
 #include <boost/thread/barrier.hpp>

folly/experimental/test/BitsTest.cpp

@@ -20,6 +20,7 @@
 
 #include <glog/logging.h>
 
+#include <folly/portability/GFlags.h>
 #include <folly/portability/GTest.h>
 
 using namespace folly;

folly/gen/test/CombineTest.cpp

@@ -21,6 +21,7 @@
 #include <folly/Range.h>
 #include <folly/gen/Base.h>
 #include <folly/gen/Combine.h>
+#include <folly/portability/GFlags.h>
 #include <folly/portability/GTest.h>
 
 using namespace folly::gen;

folly/gen/test/ParallelMapTest.cpp

@@ -21,6 +21,7 @@
 #include <folly/Memory.h>
 #include <folly/gen/Base.h>
 #include <folly/gen/ParallelMap.h>
+#include <folly/portability/GFlags.h>
 #include <folly/portability/GTest.h>
 
 using namespace folly;

folly/gen/test/ParallelTest.cpp

@@ -23,6 +23,7 @@
 
 #include <folly/gen/Base.h>
 #include <folly/gen/Parallel.h>
+#include <folly/portability/GFlags.h>
 #include <folly/portability/GTest.h>
 
 using namespace folly;

folly/memory/test/ArenaTest.cpp

@@ -16,6 +16,7 @@
 
 #include <folly/memory/Arena.h>
 #include <folly/Memory.h>
+#include <folly/portability/GFlags.h>
 #include <folly/portability/GTest.h>
 
 #include <set>

folly/synchronization/test/SmallLocksTest.cpp

@@ -28,6 +28,7 @@
 
 #include <folly/Random.h>
 #include <folly/portability/Asm.h>
+#include <folly/portability/GFlags.h>
 #include <folly/portability/GTest.h>
 #include <folly/portability/PThread.h>
 #include <folly/portability/Unistd.h>

folly/test/AtomicBitSetTest.cpp

@@ -16,6 +16,7 @@
 
 #include <folly/AtomicBitSet.h>
 
+#include <folly/portability/GFlags.h>
 #include <folly/portability/GTest.h>
 
 #include <glog/logging.h>

folly/test/FormatOtherTest.cpp

@@ -23,6 +23,7 @@
 #include <folly/Portability.h>
 #include <folly/dynamic.h>
 #include <folly/json.h>
+#include <folly/portability/GFlags.h>
 #include <folly/portability/GTest.h>
 #include <folly/small_vector.h>
 

folly/test/MPMCPipelineTest.cpp

@@ -22,6 +22,7 @@
 #include <glog/logging.h>
 
 #include <folly/Conv.h>
+#include <folly/portability/GFlags.h>
 #include <folly/portability/GTest.h>
 
 namespace folly {