Strange `transmute` term from `[u8;32]` to fieldless enum

[jberthold]

In proof test_process_set_authority_mint, a strange term was observed (and causes stuck state).
It appears to be a transmute case from a [u8] to AuthorityType (a fieldless enum).

thunk ( #discriminant ( thunk ( #cast ( Range ( ListI>
   ListItem (Integer ( ARG_UINT144:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT145:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT146:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT147:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT148:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT149:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT150:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT151:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT152:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT153:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT154:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT155:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT156:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT157:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT158:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT159:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT160:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT161:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT162:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT163:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT164:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT165:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT166:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT167:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT168:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT169:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT170:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT171:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT172:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT173:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT174:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT175:Int , 8 , false ))
   ListItem (Integer ( ARG_UINT176:Int , 8 , false ))
   ) , castKindTransmute , ty ( 600077 ) , ty ( 600197 ) ) ) , ty ( 600197 ) ) ) ) ~> .K

Note that type 600077 is u8, not [u8]. Type 600197 is AuthorityType, a fieldless enum with discriminants 0..3

• Determine where the cast from as the first step.
• This is likely related to Invalid handling of ptr offset in switchInt argument (WAS: Large getValue terms) #78 , the Range value may have been obtained from a dereferenced pointer offset and was supposed to be a single u8

[jberthold]

Possibly fixed by runtimeverification/mir-semantics#798 (not observed any more on re-run after fix), closing