svga: fix use of provoking vertex control
svga: fix use of provoking vertex control

If the SVGA3D_DEVCAP_DX_PROVOKING_VERTEX query returns false, never
define rasterizer state objects with provokingVertexLast set.  Despite
what the device reports, it may interpret the provokingVertexLast flag
anyway.  This fixes an issue when using capability clamping.

Tested with piglit provoking-vertex and glsl-fs-flat-color tests.

VMware bug 1550143.

Reviewed-by: <67ce69700661ea856134ddb10419a330e5f037d7@vmware.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler