This patch fixes all of the "easy" cases, and is _nearly_ all the way
to being able to disable useDeprecatedPositionallyEncodedOperands.
There are a small number of trickier cases, which I've split off into
the next (smaller) patch, for ease of review.
While this changes a large number of lines of source code, it produces
no significant changes in the code generated by tablegen, save for
MTVRSAVEv, which was previously encoding the wrong operand.
Also DQForm
X-Form instructions.
XXForm
DSS/DCB Form (actually misnamed X-forms...)
XLForm
XFXForm -- one codegen change, MTVRSAVEv was previously encoding the wrong operand.
XFLForm, XSForm, XOForm
AForm MForm MDForm MDSForm
VAForm Z22Form Z23Form
fixup: VAForm/VNForm
VXForm
PPC10 prefix formats
EVXForm