Moved network test buffers into heap

This is a workaround for IAR's lack of flexibility with memory regions.
Otherwise these tests would use very little heap and be mostly global
allocations.

Author: geky

features/FEATURE_LWIP/TESTS/mbedmicro-net/tcp_echo_parallel/main.cpp

@@ -87,9 +87,9 @@ class Echo {
     }
 };
 
+Echo *echoers[MBED_CFG_TCP_CLIENT_ECHO_THREADS];
 
 void test_tcp_echo_parallel() {
-    Echo echoers[MBED_CFG_TCP_CLIENT_ECHO_THREADS];
     int err = net.connect();
     TEST_ASSERT_EQUAL(0, err);
 
@@ -116,11 +116,13 @@ void test_tcp_echo_parallel() {
 
     // Startup echo threads in parallel
     for (int i = 0; i < MBED_CFG_TCP_CLIENT_ECHO_THREADS; i++) {
-        echoers[i].start();
+        echoers[i] = new Echo;
+        echoers[i]->start();
     }
 
     for (int i = 0; i < MBED_CFG_TCP_CLIENT_ECHO_THREADS; i++) {
-        echoers[i].join();
+        echoers[i]->join();
+        delete echoers[i];
     }
 
     net.disconnect();

features/FEATURE_LWIP/TESTS/mbedmicro-net/udp_echo_parallel/main.cpp

@@ -150,9 +150,9 @@ class Echo {
     }
 };
 
+Echo *echoers[MBED_CFG_UDP_CLIENT_ECHO_THREADS];
 
 void test_udp_echo_parallel() {
-    Echo echoers[MBED_CFG_UDP_CLIENT_ECHO_THREADS];
     int err = net.connect();
     TEST_ASSERT_EQUAL(0, err);
 
@@ -182,14 +182,16 @@ void test_udp_echo_parallel() {
 
         // Startup echo threads in parallel
         for (int i = 0; i < MBED_CFG_UDP_CLIENT_ECHO_THREADS; i++) {
-            echoers[i].start(i, uuid);
+            echoers[i] = new Echo;
+            echoers[i]->start(i, uuid);
         }
 
         bool result = true;
 
         for (int i = 0; i < MBED_CFG_UDP_CLIENT_ECHO_THREADS; i++) {
-            echoers[i].join();
-            result = result && echoers[i].get_result();
+            echoers[i]->join();
+            result = result && echoers[i]->get_result();
+            delete echoers[i];
         }
 
         net.disconnect();