[SR-8720] [SwiftPM] Add --hide-build option to swift run

[ddunbar]

Previous ID	SR-8720
Radar	rdar://problem/44307764
Original Reporter	@ddunbar
Type	Bug

Additional Detail from JIRA

Votes	4
Component/s	Package Manager
Labels	Bug, StarterBug
Assignee	None
Priority	Medium

md5: 242446b5c75fedfcae01e6e6a2ccfd96

Issue Description:

It is often useful to use `swift run` as a replacement for building and running.

However, for many tools which when run produce output, it is cumbersome to see the build log output. Perhaps `swift run` should have an option like `--hide-build` which hides all of the build output unless it fails. This makes it very convenient to use `swift run` as a replacement in more situations.

[aciidb0mb3r]

A possible workaround for now could be redirecting stderr to /dev/null

[ddunbar]

That works sometimes, but any sufficiently complicated UNIX-y tool will also want to use stderr

[aciidb0mb3r]

Sure, just suggesting as that is already implemented (i.e. the build output is written to stderr when using swift run)

[aciidb0mb3r]

@swift-ci create

[belkadan]

Resetting assignees for all Starter Bugs that haven't been touched since 2018.