Dump mutator lock for thread suspend timeout

Should help us see if thread suspend timeouts are due to someone
holding on the mutator lock for too long or if it is a missed
futex wake.

(cherry picked from commit f924d2381a5ea53967ba1e279766d601b9be05ea)

Bug: 17837911
Change-Id: I3417156a78f574076d5da17c86836c5a7c76084a
2 files changed