Check arguments to `llvm_var` and `llvm_ptr`
Check arguments to `llvm_var` and `llvm_ptr`

The former needs an expression referring to a non-pointer, and the
latter needs an expression referring to a pointer.

GaloisInc/saw-script,GaloisInc/saw-script,GaloisInc/saw-script,GaloisInc/saw-script,GaloisInc/saw-script