Ratified extensions dependent on unratified extensions (bit manipulation)

[jordancarlin]

Currently there are several ratified bit manipulation instructions that are defined in this repo as pseudo ops for unratified extensions. For example, rv32_zbkb contains

$pseudo_op rv64_zbp::shfli    zip rd rs1 31..25=4 24..20=15 14..12=1 6..2=4 1..0=3
$pseudo_op rv64_zbp::unshfli  unzip rd rs1 31..25=4 24..20=15 14..12=5 6..2=4 1..0=3
$pseudo_op rv64_zbb::rori     rori.rv32 rd rs1   31..25=0x30 shamtw 14..12=5 6..2=0x04 1..0=3
$pseudo_op rv64_zbp::grevi    rev8.rv32 rd rs1   31..20=0x698 14..12=5 6..0=0x13

When generating only the ratified extensions, this can cause issues. It is also not very clear from a documentation perspective. As far as I know, there are no plans to ratify zbp, so these instructions should transition to being their own instructions that don't depend on zbp.