cmd/compile/internal/ssa: split into subpackages

[matloob]

This is a massive package that takes a long time to build. Split it into smaller packages so the build could be more parallel.

[gopherbot]

Change https://go.dev/cl/800662 mentions this issue: _gen/main.go: update generator to produce changes

[gopherbot]

Change https://go.dev/cl/800661 mentions this issue: cmd/compile/internal/ssa: move Register and BlockKind to op subpackage

[gabyhelp]

Related Issues

• cmd/compile: move arch-specific rewrite rules and ops into arch-specific packages #20104
• runtime: refactor into separate subpackages #11647

Related Code Changes

• cmd/compile: move the SSA builder to ssagen/ssabuilder
• [dev.typeparams] [dev.regabi] cmd/compile: split out package ssagen [generated]

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[gopherbot]

Change https://go.dev/cl/801040 mentions this issue: generate_test: look in ssa subdirs for generated files

[gopherbot]

Change https://go.dev/cl/801040 mentions this issue: cmd/compile/internal/ssa: in generate_test look in subdirectories

[mateusz834]

This is a massive package that takes a long time to build

Not sure if this is related, but i once did CL 753380 for local dev and it speed up the gopls experience by an order of magnitude. But splitting into separate packages would obviously make it even better, without such hacks.

[prattmic]

cc @golang/compiler

[gopherbot]

Change https://go.dev/cl/803160 mentions this issue: cmd/compile/internal/ssa: move Op to op package

[gopherbot]

Change https://go.dev/cl/803601 mentions this issue: cmd/compile/internal/ssa: move Op to op package