Print out an informative comment for KILL instructions.

Print out an informative comment for KILL instructions.

The KILL pseudo-instruction may survive to the asm printer pass, just like the IMPLICIT_DEF. Print the KILL as a comment instead of just leaving a blank line in the output.

With -asm-verbose=0, a blank line is printed, like IMPLICIT?DEF.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86041 91177308-0d34-0410-b5e6-96231b3b80d8