Move the following primop rules from GHC.Base to PrelRules:

"narrow32Int#"  forall x#. narrow32Int#   x# = x#
"narrow32Word#" forall x#. narrow32Word#   x# = x#

"int2Word2Int"  forall x#. int2Word# (word2Int# x#) = x#
"word2Int2Word" forall x#. word2Int# (int2Word# x#) = x#