Set up macOS and Linux build jobs for the new `getting-started` preset

[MaxDesiatov]

Motivation

Build steps described at https://github.com/apple/swift/blob/main/docs/HowToGuides/GettingStarted.md#the-actual-build are ad-hoc and involve a lot of build options that are prone to breakage.

Proposed solution

We should group these options in a new getting-started build preset and regularly run jobs with this preset to track regressions.

Alternatives considered

No response

Additional information

No response

[art-divin]

involve a lot of build options that are prone to breakage

Thank you @MaxDesiatov for creating this issue. From my personal experience, I confirm that it is very tedious, and if I were to allow myself to be frustrated, I would be as such when something fails while following a step by step instruction according to what is described in the GettingStarted.md. To be precise:

1. --sccache for Linux is only mentioned after the "actual command for building the compiler" is mentioned; however, since Linux build is prompt to fail (in a VM), using SWIFT_USE_SCCACHE =1 environmant variable described in DevelopmentTips.md would play a significant role in improving DX. Proposal: I would expect a "1-2-3" -type of things to do, rather than different paragraphs describing different aspects of the build configuration.
2. Phrase "which can affect your debugging experience" when --release-debuginfo is explained briefly, is a little too unclear for me personally. Proposal: I would expect a table format which would describe "To debug stdlib | use --debug-swift-stdlib | it might take a while / use more RAM / disk space as mentioned in System Requirements section" - something alike for most common scenarios of building the compiler - for me it was --debug-swift --debug-swift-stdlib --debug-foundation.
3. Intellij CLion setup did not work as described in the setup. In fact, the command mentioned in the end CMake arguments from build-script by providing the -n dry-run flag; look for the last cmake command with a -G Ninja. Here is a minimal list of what you should provide to CLion here for this setting: did not output the arguments (variables) that I actually needed to set in CLion CMake settings in order to be able to run the swift-frontend, for example. I needed to use the following list:
4. It would be amazing to add VSCode setup, because in the end of the day it was the IDE that I actually was able to use to run the debugger and put a breakpoint with a least amount of hassle to go through for IDE setup.

I hope this helps 🤝