[X86] Remove encoding information from the TAILJMP instructions that are...

[X86] Remove encoding information from the TAILJMP instructions that are lowered by MCInstLowering. Fix LowerPATCHABLE_TAIL_CALL to also convert them to regular JMP/JCC instructions

There are 5 instructions here that are converted from TAILJMP opcodes to regular JMP/JCC opcodes during MCInstLowering. So normally there encoding information isn't used. The exception being when XRay wraps them in PATCHABLE_TAIL_CALL.

For the ones that weren't already handled in MCInstLowering, add handling for those and remove their encoding information.

This patch fixes PATCHABLE_TAIL_CALL to do the same opcode conversion as the regular lowering patch. Then removes the encoding information.

Differential Revision: https://reviews.llvm.org/D66561

llvm-svn: 370079