[X86] Remove MCInstLower code that drops operands from some CALL and TAILJMP...

[X86] Remove MCInstLower code that drops operands from some CALL and TAILJMP instructions. Add asserts to verify operand count

It appears the FIXME here was handled at some point. r159728 from 2012 seems to be at least aportion of fixing it.

Differential Revision: https://reviews.llvm.org/D66570

llvm-svn: 369665