[DebugInfo] Print line table extended opcode bytes if parsing fails

[DebugInfo] Print line table extended opcode bytes if parsing fails

Previously, if there was an error whilst parsing the operands of an
extended opcode, the operands would be treated as zero and printed. This
could potentially be slightly confusing. This patch changes the
behaviour to print the raw bytes instead.

Reviewed by: ikudrin

Differential Revision: https://reviews.llvm.org/D81570