Skip acquiring block-lock in BumpPointerSpace::AllocThreadUnsafe

Using it causes lock-level violation with JNI global reference table
lock. The purpose of the usage is anyways not too important.

Test: art/test/testrunner/run_build_test_target.py -j80 art-gtest-ss-gc
Bug: 160737021
Change-Id: I1042fdd1ffc9a6354ce8f628f0f5baec0d7cc0df
2 files changed