Set __get_thread()->tid as part of clone().

This was previously done only in fork() and pthread_create(), but this left raw
clone() with an invalid cached tid. Since the tid is used for pthread routines,
this led to unstable behavior after clone().

Test: ltp clone01 (see bug for more)
Test: mmma bionic/tests
Test: bionic-unit-tests-static --gtest_filter=*fork*:*clone*

Bug: 32612735
Bug: 32305649
Change-Id: I30eae5a8024b4c5da65476fcadfe14c6db35bb79