fix GL_LINE_LOOP with drivers using own render pipeline stage (#12410, #13527)

primitive needs to include the begin/end flags (broken since vbo-0.2). Should
fix missing first/last line segment on gamma, i810, i915, mga, r200, radeon,
s3v, savage, unichrome (r300 already correct). Tested on r200, fixes #13527.
9 files changed