Community build should test more parts of the compiler

[smarter]

Currently, our community build only check that compilation succeeds, we should do more:

• Compile with -Ycheck, just like in the regular tests. (Note: we should still test compilation without -Ycheck, since it can affect the order in which things are forced).
• Compile with -Ytest-pickler
• Compile with -Ythrough-tasty