Better error message needed here

[NateEpps]

Error Case "AddAdd"
Input:
>>> 2 + +
Error Output:
>>> movq $2, %rax
>>> pushq %rax
>>> ## expected NOT operator [next = '?']

"Expected NOT operator?"

well that's NOT clear

we're not expecting an operator not expecting the BOOLEAN NOT operator

[NateEpps]

I think this is fixed, need to re-run tests

[NateEpps]

Error Case "AddAdd"
Input:
>>> 2 + +
Error Output:
>>> movq $2, %rax
>>> pushq %rax
>>> ## expected non-operator [next = '?']