Allow orphaned labels in unreachabel code blocks.
Allow orphaned labels in unreachabel code blocks.

The current BB disassembler is very aggressive in validating that is has performed correctly. It expects all labels associated with a block to be associated with basic blocks. However, debug code often contains orphaned code blocks (which get parsed as padding data blocks) and these sometimes contain labels. We can safely allow these labels to be orphaned.

BUG=

Review URL: https://codereview.appspot.com/6942052

git-svn-id: db59699583a60be9a535cd09cdc9132301867226@1252 15e8cca8-e42c-11de-a347-f34a4f72eb7d

pombreda/syzygy,ericmckean/syzygy,sebmarchand/syzygy,ericmckean/syzygy,wangming28/syzygy,google/syzygy,Eloston/syzygy,supriyantomaftuh/syzygy,google/syzygy,sebmarchand/syzygy,sebmarchand/syzygy,ericmckean/syzygy,sebmarchand/syzygy,pombreda/syzygy,supriyantomaftuh/syzygy,ericmckean/syzygy,sebmarchand/syzygy,wangming28/syzygy,google/syzygy,pombreda/syzygy,wangming28/syzygy,google/syzygy,Eloston/syzygy,ericmckean/syzygy,pombreda/syzygy,supriyantomaftuh/syzygy,supriyantomaftuh/syzygy,wangming28/syzygy,pombreda/syzygy