fix #5065 - regression solving str.from_int equations now that it isn't injective any longer

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/ast/rewriter/CMakeLists.txt

@@ -33,6 +33,7 @@ z3_add_component(rewriter
     recfun_rewriter.cpp
     rewriter.cpp
     seq_axioms.cpp
+    seq_eq_solver.cpp
     seq_rewriter.cpp
     seq_skolem.cpp
     th_rewriter.cpp