Make instrumentation trampoline able to jump to jit code

In order to get the benefit of the instrumentation trampoline it must
be able to jump to jit code. This patch adds support for doing that
and adds code to ensure that we will not be jumping back and forth
between the trampoline and the interpreter all the time if the jit has
not yet compiled the current method.

Note we also disable the jit-gc when turning on these trampolines
since otherwise we could end up either sending instrumentation events
multiple times or running uninitialized memory.

Bug: 110263880
Test: ./test/testrunner/testrunner.py --host --runtime-option=-Xplugin:libtracefast-trampolined.so
Test: ./test/testrunner/testrunner.py --host --runtime-option=-Xplugin:libtracefast-trampolined.so --runtime-option=-Xjitthreshhold:0
Test: ./test.py --host

Change-Id: Ie6e92ec6367452fe4fde24d520d808b7af91d1b5