Client static destructor not running

When there are two clients with a non-debug build it appears that a static destructor in the first client does not run:
```
cd dynamorio

mkdir twoclients && cd twoclients

cat > CMakeLists.txt <<'EOF'
cmake_minimum_required(VERSION 3.7)

project(twoclients)

find_package(DynamoRIO)
if (NOT DynamoRIO_FOUND)
message(FATAL_ERROR "DynamoRIO package required to build")
endif(NOT DynamoRIO_FOUND)

add_library(client1 SHARED client1.cpp)
configure_DynamoRIO_client(client1)

add_library(client2 SHARED client2.cpp)
configure_DynamoRIO_client(client2)
EOF

cat > client1.cpp <<'EOF'
#include "dr_api.h"

#define CLIENT "client1"

class C {
public:
C() {
dr_printf("%s: constructor\n", CLIENT);
}
~C() {
dr_printf("%s: destructor\n", CLIENT);
}
};

static C global;

DR_EXPORT void
dr_client_main(client_id_t id, int argc, const char *argv[])
{
dr_set_client_name(CLIENT, "");
dr_set_client_version_string("0.1.0");
dr_printf("%s: running\n", CLIENT);
}
EOF

cat > client2.cpp <<'EOF'
#include "dr_api.h"

#define CLIENT "client2"

class C {
public:
C() {
dr_printf("%s: constructor\n", CLIENT);
}
~C() {
dr_printf("%s: destructor\n", CLIENT);
}
};

static C global;

DR_EXPORT void
dr_client_main(client_id_t id, int argc, const char *argv[])
{
dr_set_client_name(CLIENT, "");
dr_set_client_version_string("0.1.0");
dr_printf("%s: running\n", CLIENT);
}
EOF

cd ../../build
mkdir build-twoclients && cd build-twoclients
cmake -DDynamoRIO_DIR=$PWD/../cmake $PWD/../../dynamorio/twoclients
make
cd ..
bin64/drrun \
-client build-twoclients/libclient1.so 0 '' \
-client build-twoclients/libclient2.so 1 '' -- echo echo
```

With a debug build I see:
```
client1: constructor
client2: constructor
client1: running
client2: running
echo
client2: destructor
client1: destructor
```

But with a non-debug build I see:
```
client1: constructor
client2: constructor
client1: running
client2: running
echo
client2: destructor
```