DDR JIT stack walker takes insufficient parameters

[gacholio]

The !jitstack and !jitstackslots command in DDR are used to start the stack walk at a JIT frame by providing sufficient root values to walk the stack.

Currently, the root values are vmThread, SP, PC and (optionally) ELS. For a complete walk, values for j2iFrame and i2jState must also be provided (like ELS, they are currently inferred from the vmThread). The two new args should be added as optional.

j2iFrame is either NULL (if no jit->interp transition has ever taken place) or the BP value of the j2i frame.

i2jState starts off pointing to the ELS i2jState, but is updated to point into the j2i frame each time one is seen.

Almost all real-world uses of these extensions target a JIT frame very near the top of the stack, so this has not been an issue.

[gacholio]

Discovered while debugging #5449

[gacholio]

While we're at it, both the C and DDR walkers should output the j2iFrame and i2jState values at the start of the walk and when they get updated.

[gacholio]

In fact, all of the stack commands should take the new optional parameters.

[gacholio]

We will want the initial decompilation stack as an extra parameter as well.

[gacholio]

Suggest the new parm order be:

thread,pc,sp,a0,pc,literals,decomp,j2iframe,i2jstate

with the last three being optional