[to-be-committed] [RISC-V] Improve single inverted bit extraction - v3

The only change in v2 vs v3 is testsuite adjustments for the updated sequences and fixing the name of the second pattern. -- So this patch fixes a minor code generation inefficiency that (IIRC) the RAU team discovered a while ago in spec. If we want the inverted value of a single bit we can

[to-be-committed] [RISC-V] Improve single inverted bit extraction - v2

So the first version failed CI and after looking at the patch again, I think it can be improved. First, the output pattern might as well go ahead and use the zero_extract form. Second, we should be able to handle cases where all the ops are in word_mode as well as when the shift is in a na

[to-be-committed] [RISC-V] Improve single inverted bit extraction

So the first time I sent this, I attached the wrong patch. As a result the CI system wasn't happy. The second time I sent the right patch, but I don't see evidence the CI system ran the correct patch through. So I'm just starting over ;-) -- So this patch fixes a minor code generation inef