Crossgen2 crashes when compiling async methods on RISCV and LOONGARCH

[jtschuster]

See RISCV-relarted asserts commented out in #125406: https://github.com/dotnet/runtime/pull/125406/changes#diff-dd5e7e5cc30beea399eddd37ebdb26e85ced4c6052f810c97149a7975f35529bR572

[jkotas]

@dotnet/samsung

[agocke]

Thanks for filing this! It was going to be my next work item :)