A rebuilt version of libsgx_tcmalloc.a is added to fix build errors on Ubuntu16.04.

Please replace the libsgx_tcmalloc.a in the SDK installation package with this rebuilt version if you get similar link errors from sgx_tcmalloc library as below:
>>>>>>
.../sdk/gperftools/gperftools-2.5/src/system-alloc.cc:169: undefined reference to `operator delete(void*, unsigned long)'
<<<<<<