Assertion failure when recompiling primitive types from TASTy

[nicolasstucki]

We have the folllowing failure when recompileing primitivve types in the library

// failed: java.lang.AssertionError: assertion failed: class Boolean
    //   at dotty.DottyPredef$.assertFail(DottyPredef.scala:17)
    //   at dotty.tools.backend.jvm.BCodeHelpers$BCInnerClassGen.assertClassNotArrayNotPrimitive(BCodeHelpers.scala:247)
    //   at dotty.tools.backend.jvm.BCodeHelpers$BCInnerClassGen.getClassBTypeAndRegisterInnerClass(BCodeHelpers.scala:265)
    //   at dotty.tools.backend.jvm.BCodeHelpers$BCInnerClassGen.getClassBTypeAndRegisterInnerClass$(BCodeHelpers.scala:210)
    //   at dotty.tools.backend.jvm.BCodeSkelBuilder$PlainSkelBuilder.getClassBTypeAndRegisterInnerClass(BCodeSkelBuilder.scala:62)
    //   at dotty.tools.backend.jvm.BCodeHelpers$BCInnerClassGen.internalName(BCodeHelpers.scala:237)```

This can be reproduced using the tests from #9193.

We can recompile those files individually using -from-tasty or -Ythrough-tasty.