Implement jump label patching for ARC. Jump labels provide
an interface to generate dynamic branches using
self-modifying code.
This allows us to implement conditional branches where
changing branch direction is expensive but branch selection
is basically 'free'
This implementation uses 32-bit NOP and BRANCH instructions
which forced to be aligned by 4 to guarantee that they don't
cross L1 cache line boundary and can be update atomically.
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>