Backend crash when passing a field projection with a new at an inline method

[biboudis]

object Test {
  class Config(val t1: Int)

  inline def m(t2:Int) = t2

  m(new Config(3).t1)
}

Unexpected tree in genLoad: TypeTree[TypeRef(ThisType(TypeRef(ThisType(TypeRef(NoPrefix,module class <empty>)),module class Test$)),class Test$Config)]/class dotty.tools.dotc.ast.Trees$TypeTree at: <68..68>
java.lang.RuntimeException: Unexpected tree in genLoad: TypeTree[TypeRef(ThisType(TypeRef(ThisType(TypeRef(NoPrefix,module class <empty>)),module class Test$)),class Test$Config)]/class dotty.tools.dotc.ast.Trees$TypeTree at: <68..68>
        at dotty.tools.backend.jvm.DottyBackendInterface.abort(DottyBackendInterface.scala:390)
        at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoad(BCodeBodyBuilder.scala:433)
        at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoad(BCodeBodyBuilder.scala:263)
        at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoadQualifier(BCodeBodyBuilder.scala:1012)
        at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genNormalMethodCall$1(BCodeBodyBuilder.scala:784)
        at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genApply(BCodeBodyBuilder.scala:816)
        at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoad(BCodeBodyBuilder.scala:339)
        at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genStat(BCodeBodyBuilder.scala:83)
        at dotty.tools.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.$anonfun$genBlock$1(BCodeBodyBuilder.scala:920)
...

[biboudis]

@odersky If I comment out this line in computeParamBindings https://github.com/lampepfl/dotty/blob/master/compiler/src/dotty/tools/dotc/typer/Inliner.scala#L288
the test above passes. This line matches new Config(3).t1 as a SingletonType of t1:

TermRef(TypeRef(ThisType(TypeRef(ThisType(TypeRef(NoPrefix,module class <empty>)),module class Test$)),class Config),val t1)

Is this the correct SingletonType? Should it be considered even Singleton given that it has an unstable prefix? Should it have been just the ConstantType 3?

[odersky]

Thanks for the diagnostic, which was pinpointing the problem precisely!