glsl: mark some builtins with correct glsl(es) version check
GLSL Desktop spec 1.30.x: "New built-ins: trunc(), round(), roundEven(), isnan(), isinf(), modf()"
For ES, 3.00.x is the first ES spec that mentions the builtins.
Signed-off-by: Tapani Pälli tapani.palli@intel.com