glsl: Change the lexer's namespace.

glsl: Change the lexer's namespace.

Bison 3.0 removes the YYLEX_PARAM macro.  In preparation for handling
this using %lex-param, the parser needs a wrapper function for the
actual Flex lex() function.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67354
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Tested-by: Laurent Carlier <lordheavym@gmail.com>
Cc: "9.2" mesa-stable@lists.freedesktop.org