GBE: fix the large if/endif block issue.

GBE: fix the large if/endif block issue.

Some test cases have some very large block which contains
more than 32768/2 instructions which could fit into one
if/endif block.

This patch introduce a ifendif fix switch at the GenContext.
Once we encounter one of such error, we set the switch on
and then recompile the kernel. When the switch is on, we will
insert extra endif/if pair to the block to split one if/endif
block to multiple ones to fix the large if/endif issue.

Signed-off-by: Zhigang Gong <zhigang.gong@intel.com>
Reviewed-by: "Yang, Rong R" <rong.r.yang@intel.com>