Respect keep_errors flag in Parser_hack for lexer errors
Summary:
Random crash I encountered while testing unrelated changes.
Parser_hack has it's own error system, which then feeds (or not, depending on ~keep_errors) flag into global Errors module. But Parse_hack also calls into lexer, which has direct calls to Errors:
diffusion/FBS/browse/master/fbcode/hphp/hack/src/parser/lexer_hack.mll$498,513,522,530,540,548,573,617
effectively bypassing keep_errors.
Reviewed By: jamesjwu
Differential Revision:
D6393239
fbshipit-source-id:
0fa86300763f836ffcd0700a22a78e415cce9a20