Use mmap to create the pthread_internal_t

Add name to mmaped regions.
Add pthread benchmark code.
Allocate pthread_internal_t on regular stack.

Bug: 16847284
Change-Id: Id60835163bb0d68092241f1a118015b5a8f85069
Merge "Use mmap to create the pthread_internal_t"
Remove t->tls==NULL check in pthread_key_delete.

Change-Id: I6c0c71d30fe9d5b888752a4204abd95d5149bb96
Merge "Remove t->tls==NULL check in pthread_key_delete."