Decode and pretty print inline asm operand descriptors.

The INLINEASM MachineInstrs have an immediate operand describing each
original inline asm operand. Decode the bits in MachineInstr::print() so
it is easier to read:

  INLINEASM <es:rorq $1,$0>, $0:[regdef], %vreg0<def>, %vreg1<def>, $1:[imm], 1, $2:[reguse] [tiedto:$0], %vreg2, %vreg3, $3:[regdef-ec], %EFLAGS<earlyclobber,imp-def>

llvm-svn: 133901