[RISCV] Consolidate some DecoderNamespaces for standard extensions. (#128954)

First thing to know is that the subtarget feature checks used to block
accessing a decoder table are only a performance optimization and not
required for functionality. The tables have their own predicate checks.
I've removed them from all the standard extension tables.

-RV32 Zacas decoder namespace has been renamed to RV32GPRPair, I think
Zilsd(rv32 load/store pair) can go in here too.
-The RV32 Zdinx table has been renamed to also use RV32GPRPair.
-The Zfinx table has been renamed to remove superflous "RV" prefix.
-Zcmp and Zcmt tables have been combined into a ZcOverlap table. I think
 Zclsd(rv32 compressed load/store pair) can go in here too.
-All the extra standard extension tables are checked after the main
 standard extension table. This makes the common case of the main table
 matching occur earlier.
-Zicfiss is the exception to this as it needs to be checked before
 the main table since it overrides some encodings from Zcmop. This
can't be handled by a predicate based priority as Zicfiss only overrides
 a subset of Zcmop encodings.

0 files changed, 0 insertions, 0 deletions