Revert "For disassembly when adding a symbolic operand that is a C++ symbol...

Revert "For disassembly when adding a symbolic operand that is a C++ symbol name, also put the human readable name in a comment."

This reverts commit r198441.

This change doesn't build on Windows, and doesn't do the right thing on
Linux and other platforms that don't use a _Z prefix instead of __Z for
C++ names.

It also had no tests, so it wasn't clear how to fix it forward.

llvm-svn: 198445