This patch enables instructions that are destructive on their
destination- and first source operand, to be prefixed with a
MOVPRFX instruction.
This patch also adds a variety of tests:
- positive tests for all instructions and forms that accept a movprfx for either or both predicated and unpredicated forms.
- negative tests for all instructions and forms that do not accept an unpredicated or predicated movprfx.
- negative tests for the diagnostics that get emitted when a MOVPRFX instruction is used incorrectly.
This is patch [2/2] in a series to add MOVPRFX instructions:
- Patch [1/2]: https://reviews.llvm.org/D49592
- Patch [2/2]: https://reviews.llvm.org/D49593