bvarray2uf assertion violation at ../src/tactic/bv/bvarray2uf_rewriter.cpp Line: 396

Hi,
For this formula:
```
(declare-fun a (Int) Bool)
(assert (exists ((b Int)) (a 0)))
(check-sat-using bvarray2uf)
```
Z3  throws out an assertion violation:
```
NOT IMPLEMENTED YET!
ASSERTION VIOLATION
File: ../src/tactic/bv/bvarray2uf_rewriter.cpp
Line: 396
UNREACHABLE CODE WAS REACHED.
(C)ontinue, (A)bort, (S)top, (T)hrow exception, Invoke (G)DB
```

OS: Ubuntu 18.04
Commit: 2882a67
