mirage/mirage-skeleton: PR #328: Be able to define multiple overlays and add them when we compile mirage-skeleton

@ac734e6

Stages:

• ❌ x86_64-debian-10-4.13 (2m07s)
• 🟡 arm64-debian-10-4.13

History:

• 26/01/2022 11:11 🟡 @cb0217c (14m25s)
• 26/01/2022 09:47 🟡 @6b89f88 (13m36s)
• 26/01/2022 09:42 🟠 @0084a2a
• 26/01/2022 09:39 🟡 @ec0e661
• 25/01/2022 21:36 ❌ @6021a21 (4m30s)
• 25/01/2022 20:41 ❌ @d753706 (2m38s)
• 25/01/2022 20:34 ❌ @a26b67a (54s)
• 25/01/2022 20:31 ❌ @ac734e6 (2m07s)
• 25/01/2022 20:26 ❌ @2b54be2 (1m50s)
• 25/01/2022 20:23 ❌ @2210f9d (1m28s)