3808ba78de
Use VPIRBasicBlock to wrap the middle block and implement patching up branches in predecessors in VPIRBasicBlock::execute. The IR middle block is only created after skeleton creation. Initially a regular VPBasicBlock is created, which will later be replaced by a VPIRBasicBlock once the middle IR basic block has been created. Note that this slightly changes the order of instructions created in the middle block; code generated by recipe execution in the middle block will now be inserted before the terminator (and in between the compare to used by the terminator). The original order will be restored in https://github.com/llvm/llvm-project/pull/92651. PR: https://github.com/llvm/llvm-project/pull/95816