Revert "[i965] renable regative rhw test"

This reverts commit 3158e981f5.
rhw issue has gone away on IGD.

src/mesa/drivers/dri/i965/brw_clip_line.c

@@ -148,10 +148,12 @@ static void clip_and_emit_line( struct brw_clip_compile *c )
    brw_clip_init_clipmask(c);
 
    /* -ve rhw workaround */
-   brw_set_conditionalmod(p, BRW_CONDITIONAL_NZ);
-   brw_AND(p, brw_null_reg(), get_element_ud(c->reg.R0, 2),
-		   brw_imm_ud(1<<20));
-   brw_OR(p, c->reg.planemask, c->reg.planemask, brw_imm_ud(0x3f));
+   if (!BRW_IS_IGD(p->brw)) {
+      brw_set_conditionalmod(p, BRW_CONDITIONAL_NZ);
+      brw_AND(p, brw_null_reg(), get_element_ud(c->reg.R0, 2),
+              brw_imm_ud(1<<20));
+      brw_OR(p, c->reg.planemask, c->reg.planemask, brw_imm_ud(0x3f));
+   }
 
    brw_set_predicate_control(p, BRW_PREDICATE_NONE);
 

src/mesa/drivers/dri/i965/brw_clip_tri.c

@@ -536,14 +536,16 @@ void brw_emit_tri_clip( struct brw_clip_compile *c )
 
    /* if -ve rhw workaround bit is set, 
       do cliptest */
-   brw_set_conditionalmod(p, BRW_CONDITIONAL_NZ);
-   brw_AND(p, brw_null_reg(), get_element_ud(c->reg.R0, 2), 
-		   brw_imm_ud(1<<20));
-   neg_rhw = brw_IF(p, BRW_EXECUTE_1); 
-   {
-	   brw_clip_test(c);
+   if (!BRW_IS_IGD(p->brw)) {
+      brw_set_conditionalmod(p, BRW_CONDITIONAL_NZ);
+      brw_AND(p, brw_null_reg(), get_element_ud(c->reg.R0, 2), 
+              brw_imm_ud(1<<20));
+      neg_rhw = brw_IF(p, BRW_EXECUTE_1); 
+      {
+         brw_clip_test(c);
+      }
+      brw_ENDIF(p, neg_rhw);
    }
-   brw_ENDIF(p, neg_rhw);
    /* Can't push into do_clip_tri because with polygon (or quad)
     * flatshading, need to apply the flatshade here because we don't
     * respect the PV when converting to trifan for emit:

src/mesa/drivers/dri/i965/brw_vs_emit.c

@@ -867,7 +867,7 @@ static void emit_vertex_write( struct brw_vs_compile *c)
        * Later, clipping will detect ucp[6] and ensure the primitive is
        * clipped against all fixed planes.
        */
-      if (!c->key.know_w_is_one) {
+      if (!BRW_IS_IGD(p->brw) && !c->key.know_w_is_one) {
 	 brw_CMP(p,
 		 vec8(brw_null_reg()),
 		 BRW_CONDITIONAL_L,