Improve pthread_create failure handling.

Return EAGAIN rather than aborting if we fail to set up the TLS for a new
thread.

Add a test that uses all the VMAs so we can properly test these edge cases.

Add an explicit test for pthread_attr_setdetachstate, which we use in the
previous test, but other than that has no tests.

Remove support for ro.logd.timestamp/persist.logd.timestamp, which doesn't
seem to be used, and which prevents us from logging failures in cases where
mmap fails (because we need to mmap in the system property implementation).

(cherry picked from commit 53dc9dd7)

Bug: http://b/65608572
Test: ran tests
Change-Id: I881029d9fd368b8556843e70fdb278fbe51dbfee