Add support of afl-fuzzer.

Related issue: #333, #454

Works only with default libc:
```
$ make debug.linux -j TOOLCHAIN="./build/configs/toolchain_afl.cmake" USE_COMPILER_DEFAULT_LIBC=YES
```

JerryScript-DCO-1.0-Signed-off-by: Ruben Ayrapetyan r.ayrapetyan@samsung.com
JerryScript-DCO-1.0-Signed-off-by: Evgeny Gavrin e.gavrin@samsung.com

jerry-core/jrt/jrt-fatals.cpp

@@ -60,7 +60,9 @@ jerry_fatal (jerry_fatal_code_t code) /**< status code */
   }
 #endif /* !JERRY_NDEBUG */
 
-  if (code != 0 && jerry_is_abort_on_fail ())
+  if (code != 0
+      && code != ERR_OUT_OF_MEMORY
+      && jerry_is_abort_on_fail ())
   {
     abort ();
   }