CL 570681 ("os: make FindProcess use pidfd on Linux") mentions accepted proposal go.dev/issue/51246 (described as fully implemented in Go 1.22) and NeedsInvestigation continuation issue go.dev/issue/62654.

(MOVWreg (MOVDconst [c])) => (MOVDconst [int64(int32(c))])
(MOVWZreg (MOVDconst [c])) => (MOVDconst [int64(uint32(c))])

// Implement clrsldi and clrslwi extended mnemonics as described in
// ISA 3.0 section C.8. AuxInt field contains values needed for
// the instructions, packed together since there is only one available.

Starting with go1.19.txt, each API feature line must end in "#nnnnn"
giving the GitHub issue number of the proposal issue that accepted
the new API. This helps with our end-of-cycle audit of new APIs.
The same requirement applies to next/* (described below), which will
become a go1.XX.txt for XX >= 19.

The next/ directory contains the only files intended to be mutated.
Each file in that directory contains a list of features that may be added