i965/disasm: "Handle" Gen8+ HF/DF immediate cases.

We should print something properly, but I'm not sure how to properly
print an HF, and we don't have any DFs today to test with.

This is at least better than the current Gen8 disassembler, which would
simply assert fail.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>

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

@@ -981,6 +981,13 @@ imm(FILE *file, struct brw_context *brw, unsigned type, brw_inst *inst)
       break;
    case BRW_HW_REG_TYPE_F:
       format(file, "%-gF", brw_inst_imm_f(brw, inst));
+      break;
+   case GEN8_HW_REG_IMM_TYPE_DF:
+      string(file, "Double IMM");
+      break;
+   case GEN8_HW_REG_IMM_TYPE_HF:
+      string(file, "Half Float IMM");
+      break;
    }
    return 0;
 }