Expose functionality for building crucible FnHandles from stubs FunctionOverrides

[RyanGlScott]

stubs-common defines functionality for turning a FunctionOverride into an FnHandle suitable for use within crucible:

stubs/stubs-common/src/Stubs/Memory/Common.hs

Lines 401 to 443 in 2d6fe1b

	mkAndBindOverride :: forall fnArgs fnRet rtp blocks r ctx
	. LCS.CrucibleState p sym ext rtp blocks r ctx
	-> AF.FunctionOverride p sym fnArgs arch fnRet
	-> [ AF.SomeFunctionOverride p sym arch ]
	-> IO ( LCF.FnHandle args ret
	, LCS.CrucibleState p sym ext rtp blocks r ctx
	)
	mkAndBindOverride state0 fnOverride parents = do
	-- First, construct an override for the function.
	let retOV :: forall r'
	. LCSO.OverrideSim p sym ext r' args ret
	(Ctx.Assignment (LCS.RegValue' sym)
	(DMS.CtxToCrucibleType (DMS.ArchRegContext arch)))
	retOV = do
	mem <- LCS.readGlobal $ SM.imMemVar initialMem
	argMap <- LCS.getOverrideArgs
	let argReg = massageRegAssignment $ LCS.regMap argMap
	(args, getVarArg) <- liftIO $
	SM.functionIntegerArguments abi bak
	(AF.functionArgTypes fnOverride)
	argReg mem
	retVal <- AF.functionOverride fnOverride bak args getVarArg parents
	SM.functionIntegerReturnRegisters abi bak archVals
	(AF.functionReturnType fnOverride)
	retVal
	argReg
	let ov :: LCSO.Override p sym ext args ret
	ov = LCSO.mkOverride' (AF.functionName fnOverride) regsRepr retOV
	-- Next, register any externs, auxiliary functions, or forward
	-- declarations that are used in the override.
	let LCS.FnBindings curHandles = state0 ^. LCS.stateContext ^. LCS.functionBindings
	let curGlobals = state0 ^. LCSE.stateGlobals
	(newHandles, newGlobals) <-
	insertFunctionOverrideReferences bak abi fnOverride curHandles curGlobals
	let state1 = state0 & LCS.stateContext . LCS.functionBindings
	.~ LCS.FnBindings newHandles
	& LCSE.stateGlobals
	.~ newGlobals
	-- Finally, build a function handle for the override and insert it into
	-- the state.
	bindOverrideHandle state1 hdlAlloc (Ctx.singleton regsRepr) crucRegTypes ov

Unfortunately, this functionality is defined as a local function within Stubs.Memory.Common.lookupFunction, which makes it impossible to use by downstream clients. We should factor out the relevant bits of mkAndBindOverride into top-level functions that can be called independently.