Re: pg_plan_advice: add NO_ scan and join method tags

Hi Florin,
I tested the patch on current master, and it worked well in my testing.
Before applying the patch, advice such as NO_SEQ_SCAN(t1) was rejected
with a parser error because the NO_ scan and join tags were not
supported.
After applying the patch, the new NO_ tags were accepted successfully.
I verified that:
NO_SEQ_SCAN prevented the planner from using a Sequential Scan when
another eligible scan method was available.
NO_HASH_JOIN caused the planner to choose an alternative join method.
Multiple NO_ advice tags worked as expected.
Conflicting positive and negative advice for the same method was
detected correctly.
Positive and negative advice for different methods worked together as expected.
I also ran the regression tests, and everything completed successfully.

Thanks for working on this enhancement.

Regards

solai