Adds the "Vector Bit Manipulation Instructions 2" instruction set.
These new instructions are added via the `opcodesextra` mechanism #345, since
they're missing from the opcodes database.
Contributed by @vsivsi. Extracted from #349 with simplifications.
Specifically, as prompted by the `dupl` linter we extract some common forms
lists into a helper `forms.go` file.
Co-authored-by: Vaughn Iverson <vsivsi@yahoo.com>
Adds the VPOPCNTDQ instruction set, providing packed population count for
double and quadword integers.
These are added via the `opcodesextra` mechanism #345, since they're missing
from the opcodes database. In this case the 512-bit non-AVX512VL forms are
added here as well as the opcodes database, but they're deduplicated later.
Contributed by @vsivsi. Extracted from #234 with simplifications for AVX-512
form expansion.
Co-authored-by: Vaughn Iverson <vsivsi@yahoo.com>
