jit: Update _gst_ip correctly when the method_prologue is left

This has been found with the DebugTools tests and the most simple
re-producer is:

  ([3+3] newProcess singleStep; suspend; suspendedContext) inspect.

The check for _gst_except_flag is triggerred in the method prologue
and the JIT returns to the interpreter loop. When the process is
switched an old _gst_ip was written to context->ipOffset. Modify the
emit_interrupt_check to take an optional ipOffset parameter that will
be stored when the interrupt check triggers. For primitives it is
not clear which ipOffset should be saved.

2013-12-23  Holger Hans Peter Freyther  <holger@moiji-mobile.com>

	* xlat.c: Add ipOffset parameter to emit_interrupt_check.
jit: Resume the method _after_ the interrupt check

For single stepping through a method we should continue _after_ the
interrupt check or otherwise the interrupt check will _always_
trigger. Make sure to align the label properly otherwise the returned
native_ip will be turned into DUMMY_NATIVE_IP. This removes the
deadlocks inside the DebugTools test package.

2013-12-23  Holger Hans Peter Freyther  <holger@moiji-mobile.com>

	* xlat.c: Change emitted code in emit_interrupt_check.