Define ARENA_DEBUG in Travis test runs

The definition and uses of Arena::walk() are compiled only if
ARENA_DEBUG is defined. Configure Travis to define ARENA_DEBUG so
compilation errors do not go unnoticed.

ci/test/00_setup_env_native_asan.sh

@@ -9,4 +9,4 @@ export LC_ALL=C.UTF-8
 export PACKAGES="clang llvm python3-zmq qtbase5-dev qttools5-dev-tools libssl1.0-dev libevent-dev bsdmainutils libboost-system-dev libboost-filesystem-dev libboost-chrono-dev libboost-test-dev libboost-thread-dev libdb5.3++-dev libminiupnpc-dev libzmq3-dev libqrencode-dev"
 export NO_DEPENDS=1
 export GOAL="install"
-export BITCOIN_CONFIG="--enable-zmq --with-incompatible-bdb --with-gui=qt5 CPPFLAGS=-DDEBUG_LOCKORDER --with-sanitizers=address,integer,undefined CC=clang CXX=clang++"
+export BITCOIN_CONFIG="--enable-zmq --with-incompatible-bdb --with-gui=qt5 CPPFLAGS='-DARENA_DEBUG -DDEBUG_LOCKORDER' --with-sanitizers=address,integer,undefined CC=clang CXX=clang++"

ci/test/00_setup_env_native_tsan.sh

@@ -10,4 +10,4 @@ export DOCKER_NAME_TAG=ubuntu:16.04
 export PACKAGES="clang llvm python3-zmq qtbase5-dev qttools5-dev-tools libssl-dev libevent-dev bsdmainutils libboost-system-dev libboost-filesystem-dev libboost-chrono-dev libboost-test-dev libboost-thread-dev libdb5.3++-dev libminiupnpc-dev libzmq3-dev libqrencode-dev"
 export NO_DEPENDS=1
 export GOAL="install"
-export BITCOIN_CONFIG="--enable-zmq --disable-wallet --with-gui=qt5 CPPFLAGS=-DDEBUG_LOCKORDER --with-sanitizers=thread --disable-hardening --disable-asm CC=clang CXX=clang++"
+export BITCOIN_CONFIG="--enable-zmq --disable-wallet --with-gui=qt5 CPPFLAGS='-DARENA_DEBUG -DDEBUG_LOCKORDER' --with-sanitizers=thread --disable-hardening --disable-asm CC=clang CXX=clang++"