v2 (Ian Romanick)
- Move the check to the lexer before rallocing a copy of the large string.
Fixes the following 2 dEQP tests:
dEQP-GLES3.functional.shaders.keywords.invalid_identifiers.max_length_vertex
dEQP-GLES3.functional.shaders.keywords.invalid_identifiers.max_length_fragment
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>