add recfun rewriting, remove quantifier based recfun

src/ast/rewriter/recfun_rewriter.cpp

@@ -0,0 +1,39 @@
+/*++
+Copyright (c) 2018 Microsoft Corporation
+
+Module Name:
+
+    recfun_rewriter.cpp
+
+Abstract:
+
+    Rewriter recursive function applications to values
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2020-04-26
+
+
+--*/
+
+
+#include "ast/rewriter/recfun_rewriter.h"
+#include "ast/rewriter/var_subst.h"
+    
+br_status recfun_rewriter::mk_app_core(func_decl * f, unsigned num_args, expr * const * args, expr_ref & result) {
+    if (m_rec.is_defined(f)) {
+        for (unsigned i = 0; i < num_args; ++i) {
+            if (!m.is_value(args[i]))
+                return BR_FAILED;
+        }
+        recfun::def const& d = m_rec.get_def(f);
+        var_subst sub(m);
+        result = sub(d.get_rhs(), num_args, args);
+        return BR_REWRITE_FULL;
+    }
+    else {
+        return BR_FAILED;
+    }
+}
+
+