I want to be able to trace during global object construction.
mbed_trace_init() must be called before tr_info() will function.
And mbed_trace_init() relies on malloc() so that function must be called after the malloc_mutex has been created.
This could be achieved by allowing static configuration of mbed_trace
Or it could be achieved by a weak “pre-init” hook function that is called just prior to __libc_init_array()