cpu/esp_common/syscalls.c💯 error (memleak): Memory leak: mtx
cpu/esp_common/syscalls.c:131: error (memleak): Memory leak: rmtx
cpu/esp_common/syscalls.c:365: error (comparePointers): Subtracting pointers that point to different objects
cpu/esp_common/thread_arch.c:355: error (comparePointers): Comparing pointers that point to different objects
cpu/esp8266/startup.c:59: error (comparePointers): Subtracting pointers that point to different objects
If esp_idf_heap is not used, implement calloc through a custom wrapper
function on top of malloc to add overflow detection, which is not
present in the newlib forks with xtensa support yet.
