mesa: get the translation from mesa 2d regs to tgsi working

first working version of arb_geometry_shader4

src/mesa/state_tracker/st_program.c

@@ -492,6 +492,9 @@ st_translate_geometry_program(struct st_context *st,
    /* which vertex output goes to the first geometry input */
    vslot = 0;
 
+   memset(inputMapping, 0, sizeof(inputMapping));
+   memset(outputMapping, 0, sizeof(outputMapping));
+
    /*
     * Convert Mesa program inputs to TGSI input register semantics.
     */