Fix platform 10 build with folly (facebook#10708)

Summary:
Change the library order in PLATFORM_LDFLAGS to enable fbcode platform 10 build with folly. This PR also has a few fixes for platform 10 compiler errors.

Pull Request resolved: facebook#10708

Test Plan:
ROCKSDB_FBCODE_BUILD_WITH_PLATFORM010=1 USE_COROUTINES=1 make -j64 check
ROCKSDB_FBCODE_BUILD_WITH_PLATFORM010=1 USE_FOLLY=1 make -j64 check

Reviewed By: ajkr

Differential Revision: D39666590

Pulled By: anand1976

fbshipit-source-id: 256a1127ef561399cd6299a6a392ca29bd68ca44

Makefile

@@ -509,7 +509,7 @@ ifneq ($(strip $(FOLLY_PATH)),)
 
 	# Add -ldl at the end as gcc resolves a symbol in a library by searching only in libraries specified later
 	# in the command line
-	PLATFORM_LDFLAGS += $(BOOST_PATH)/lib/libboost_context.a $(BOOST_PATH)/lib/libboost_filesystem.a $(BOOST_PATH)/lib/libboost_atomic.a $(BOOST_PATH)/lib/libboost_program_options.a $(BOOST_PATH)/lib/libboost_regex.a $(BOOST_PATH)/lib/libboost_system.a $(BOOST_PATH)/lib/libboost_thread.a $(DBL_CONV_PATH)/lib/libdouble-conversion.a $(FOLLY_PATH)/lib/libfolly.a $(FMT_LIB_PATH)/libfmt.a $(GLOG_LIB_PATH)/libglog.so $(GFLAGS_PATH)/lib/libgflags.so.2.2 -ldl
+	PLATFORM_LDFLAGS += $(FOLLY_PATH)/lib/libfolly.a $(BOOST_PATH)/lib/libboost_context.a $(BOOST_PATH)/lib/libboost_filesystem.a $(BOOST_PATH)/lib/libboost_atomic.a $(BOOST_PATH)/lib/libboost_program_options.a $(BOOST_PATH)/lib/libboost_regex.a $(BOOST_PATH)/lib/libboost_system.a $(BOOST_PATH)/lib/libboost_thread.a $(DBL_CONV_PATH)/lib/libdouble-conversion.a $(FMT_LIB_PATH)/libfmt.a $(GLOG_LIB_PATH)/libglog.so $(GFLAGS_PATH)/lib/libgflags.so.2.2 $(LIBEVENT_PATH)/lib/libevent-2.1.so -ldl
 	PLATFORM_LDFLAGS += -Wl,-rpath=$(GFLAGS_PATH)/lib -Wl,-rpath=$(GLOG_LIB_PATH) -Wl,-rpath=$(LIBEVENT_PATH)/lib -Wl,-rpath=$(LIBSODIUM_PATH)/lib -Wl,-rpath=$(LIBEVENT_PATH)/lib
 endif
 	PLATFORM_CCFLAGS += -DUSE_FOLLY -DFOLLY_NO_CONFIG

db/db_impl/db_impl.cc

@@ -1438,11 +1438,11 @@ Status DBImpl::FlushWAL(bool sync) {
       // future writes
       IOStatusCheck(io_s);
       // whether sync or not, we should abort the rest of function upon error
-      return std::move(io_s);
+      return static_cast<Status>(io_s);
     }
     if (!sync) {
       ROCKS_LOG_DEBUG(immutable_db_options_.info_log, "FlushWAL sync=false");
-      return std::move(io_s);
+      return static_cast<Status>(io_s);
     }
   }
   if (!sync) {
@@ -1551,15 +1551,15 @@ Status DBImpl::ApplyWALToManifest(VersionEdit* synced_wals) {
 Status DBImpl::LockWAL() {
   log_write_mutex_.Lock();
   auto cur_log_writer = logs_.back().writer;
-  auto status = cur_log_writer->WriteBuffer();
+  IOStatus status = cur_log_writer->WriteBuffer();
   if (!status.ok()) {
     ROCKS_LOG_ERROR(immutable_db_options_.info_log, "WAL flush error %s",
                     status.ToString().c_str());
     // In case there is a fs error we should set it globally to prevent the
     // future writes
     WriteStatusCheck(status);
   }
-  return std::move(status);
+  return static_cast<Status>(status);
 }
 
 Status DBImpl::UnlockWAL() {

table/plain/plain_table_builder.cc

@@ -277,7 +277,7 @@ Status PlainTableBuilder::Finish() {
   IOStatus s = WriteBlock(property_block_builder.Finish(), file_, &offset_,
                           &property_block_handle);
   if (!s.ok()) {
-    return std::move(s);
+    return static_cast<Status>(s);
   }
   meta_index_builer.Add(kPropertiesBlockName, property_block_handle);