Experimental parser: Add an option to lexer shell to ignore after ILLEGAL.

Experimental parser: Add an option to lexer shell to ignore after ILLEGAL.

(We'll check that the experimental lexer produces and ILLEGAL with the same
start position, and then ignore the rest of the token stream.)

With this change, we have 23 failures.

TBR=dcarney@chromium.org
BUG=

Committed: https://code.google.com/p/v8/source/detail?r=17705

[marja, 2013-11-13 16:25:34]

Committed patchset #1 manually as r17705 (presubmit successful).