Update run-test script to pass --Xjitthreshold:0 for jvmti tests

To provide better test coverage for jvmti + jit, lower the
jit threshold to 0 so we jit on the first use of the function.

Test: art/testrunner.py
Change-Id: Ida0edfccd3ae3f4990f6e863f1db00c0a210803b
1 file changed