Disable JIT GC when JitAtFirstUse is enabled

JitAtFirstUse + JIT GC are causing few deadlocks, so disabling
JITGC for now.

bug: 147208992
Test: art/test.py --jit-on-first-use
Change-Id: Ia10e203ce7ea3709527e3c9f44a1488629472842
1 file changed