Parallel builds

[zsilbi]

Describe the feature

Build entries are independent and could be processed concurrently.
Probably it only makes sense for larger projects with lots of entries where isolatedDeclarations can't be used for declarations emit, since spawning a child process can be slower than processing everything in one go.

Workers could be spawned for each entry (limited by CPU core count), and optionally the main thread could also be used for the largest entry.

Additional information

• Would you be willing to help implement this feature?

[zsilbi]

Probably it only makes sense for larger projects with lots of entries where isolatedDeclarations can't be used for declarations emit, since spawning a child process can be slower than processing everything in one go.

I did some testing and if we dynamicly to load the bundler or transformer builders based on entry type this is no longer true.

This also decreases the total time spent for cases where there are only one type of entries used. (by about 200-300ms in my measurements)