saw-script should let you specify initial values of function-pointer arguments

[brianhuffman]

The llvm_assert_eq command lets you specify the initial value of an LLVM variable, but only for basic types (ints; arrays or structs of ints) that are given as Cryptol expressions.

We need a similar command for function pointer arguments, where we can specify the initial value as an LLVM function name. (It might also be useful to have another command variant that takes a Cryptol expression of the appropriate function type instead.)

[brianhuffman]

Commit 75feac1 in the crucible-integration branch adds a saw-script function crucible_global that should eventually be able to do what we want. Given a string, it returns a pointer value that points to the named global constant. However, it currently works only for pointers to data, and not function pointers.

[brianhuffman]

As of 9a8198e, crucible_global also works with function names.