mesa: Move the mvp_with_dp4 flag to ShaderCompilerOptions.

This flag essentially tells the compiler whether it prefers
dot products or multiply/adds for matrix operations.  As such,
ShaderCompilerOptions seems like the right place for it.

This also lets us specify it on a per-stage basis.  This patch makes all
existing users set the flag for the Vertex Shader stage only, as it's
currently only used for fixed-function vertex programs.  That will
change soon, and I wanted to preserve the existing behavior.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>

src/mesa/main/context.c

@@ -1720,18 +1720,6 @@ _mesa_Flush(void)
 }
 
 
-/**
- * Set mvp_with_dp4 flag.  If a driver has a preference for DP4 over
- * MUL/MAD, or vice versa, call this function to register that.
- * Otherwise we default to MUL/MAD.
- */
-void
-_mesa_set_mvp_with_dp4( struct gl_context *ctx,
-                        GLboolean flag )
-{
-   ctx->mvp_with_dp4 = flag;
-}
-
 /*
  * ARB_blend_func_extended - ERRORS section
  * "The error INVALID_OPERATION is generated by Begin or any procedure that