base: Ensure that ghc-bignum builds before GHC.IO.Encoding.Iconv
On Windows GHC.IO.Encoding.Iconv
is empty and has no dependencies.
Consequently, we must add dummy build ordering imports to ensure that,
e.g., GHC.Types
and GHC.BigNum.Nat
are built before
GHC.IO.Encoding.Iconv
.