Add the ability to generate programs that doesn't use condition codes.

ctx->Shader.EmitCondCodes determines if we use condition codes.
If not, IF statement uses first operand's X component as the condition.
Added OPCODE_BRK0, OPCODE_BRK1, OPCODE_CONT0, OPCODE_CONT1 to handle
the common cases of conditional break/continue.
diff --git a/src/mesa/shader/prog_instruction.c b/src/mesa/shader/prog_instruction.c
index ed479a7..272caf6 100644
--- a/src/mesa/shader/prog_instruction.c
+++ b/src/mesa/shader/prog_instruction.c
@@ -138,9 +138,13 @@
    { OPCODE_BGNSUB, "BGNSUB", 0 },
    { OPCODE_BRA,    "BRA",   0 },
    { OPCODE_BRK,    "BRK",   0 },
+   { OPCODE_BRK0,   "BRK0",  1 },
+   { OPCODE_BRK1,   "BRK1",  1 },
    { OPCODE_CAL,    "CAL",   0 },
    { OPCODE_CMP,    "CMP",   3 },
-   { OPCODE_CONT,   "CONT",  1 },
+   { OPCODE_CONT,   "CONT",  0 },
+   { OPCODE_CONT0,  "CONT0", 1 },
+   { OPCODE_CONT1,  "CONT1", 1 },
    { OPCODE_COS,    "COS",   1 },
    { OPCODE_DDX,    "DDX",   1 },
    { OPCODE_DDY,    "DDY",   1 },