Implement LogLineLowStack() properly.

Avoid stack-based buffers used by the log formatting in
__android_log_print().

Move the VLOG(threads) in Thread::InitStackHwm() after the
low stack check as it's not safe to actually log before
that; even the StringPrintf() is using a stack-based buffer.

Bug: 18830897
Change-Id: I13b2166438e871c52ab91dabfe98f2200fd7c1cf
2 files changed