Switch to Mesa 7.9.

media-libs/mesa/files/7.9-conditional-discards.patch

+From ead2ea89f42b40edc56ddf8c6ce1df4efdcefe2a Mon Sep 17 00:00:00 2001
+From: Marek Olšák <maraeo@gmail.com>
+Date: Thu, 25 Nov 2010 11:13:36 +0000
+Subject: ir_to_mesa: Add support for conditional discards.
+
+NOTE: This is a candidate for the 7.9 branch.
+
+Signed-off-by: Marek Olšák <maraeo@gmail.com>
+Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
+---
+diff --git a/src/mesa/program/ir_to_mesa.cpp b/src/mesa/program/ir_to_mesa.cpp
+index 8f75c82..5dd602f 100644
+--- a/src/mesa/program/ir_to_mesa.cpp
++++ b/src/mesa/program/ir_to_mesa.cpp
+@@ -2166,9 +2166,14 @@ ir_to_mesa_visitor::visit(ir_discard *ir)
+ {
+    struct gl_fragment_program *fp = (struct gl_fragment_program *)this->prog;
+ 
+-   assert(ir->condition == NULL); /* FINISHME */
++   if (ir->condition) {
++      ir->condition->accept(this);
++      this->result.negate = ~this->result.negate;
++      ir_to_mesa_emit_op1(ir, OPCODE_KIL, ir_to_mesa_undef_dst, this->result);
++   } else {
++      ir_to_mesa_emit_op0(ir, OPCODE_KIL_NV);
++   }
+ 
+-   ir_to_mesa_emit_op0(ir, OPCODE_KIL_NV);
+    fp->UsesKill = GL_TRUE;
+ }
+ 
+--
+cgit v0.8.3-6-g21f6