allocCStringArray to a constant fails with nontelling Error

[Clyybber]

On latest devel
const deviceExtensions = allocCStringArray(["somestring"])
fails with
lib/system.nim(3178, 16) Error: VM is only allowed to 'cast' between integers of same size

[Clyybber]

Stack trace with koch:

  const deviceExtensions = allocCStringArray(["somestring"])
  ^
lib/system.nim(3206, 16) Error: VM is only allowed to 'cast' between integers of same size
        result = cast[cstringArray](alloc0((a.len+1) * sizeof(cstring)))
                 ^
Traceback (most recent call last)
nim.nim(133) nim
nim.nim(97) handleCmdLine
main.nim(162) mainCommand
main.nim(73) commandCompileToC
modules.nim(124) compileProject
modules.nim(71) compileModule
passes.nim(194) processModule
passes.nim(103) processTopLevelStmt
sem.nim(592) myProcess
sem.nim(560) semStmtAndGenerateGenerics
semstmts.nim(1894) semStmt
semexprs.nim(908) semExprNoType
semexprs.nim(2536) semExpr
semstmts.nim(598) semConst
sem.nim(350) semConstExpr
vm.nim(1819) evalConstExpr
vm.nim(1815) evalConstExprAux
vm.nim(988) rawExecute vm.nim(394)
compile vmgen.nim(2055) genProc
vmgen.nim(258) gen
vmgen.nim(1865) gen
vmgen.nim(258) gen
vmgen.nim(1838) gen
vmgen.nim(1424) genAsgn
vmgen.nim(253) gen
vmgen.nim(1914) gen
vmgen.nim(805) genIntCast
msgs.nim(507) globalError
msgs.nim(495) liMessage
msgs.nim(329) handleError
msgs.nim(314) quit
FAILURE

[Clyybber]

Now gives lib/system.nim(2189, 13) Error: VM does not support 'cast' from tyOpenArray to tyPtr which is good enough IMO.