Reorganizing source code. Created util dir

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

src/util/approx_set.cpp

@@ -0,0 +1,52 @@
+/*++
+Copyright (c) 2006 Microsoft Corporation
+
+Module Name:
+
+    approx_set.cpp
+
+Abstract:
+
+    Approximated sets.
+
+Author:
+
+    Leonardo de Moura (leonardo) 2007-03-02.
+
+Revision History:
+
+--*/
+
+#include"approx_set.h"
+
+void approx_set::display(std::ostream & out) const {
+    out << "{";
+    bool first = true;
+    unsigned long long s = m_set;
+    for (unsigned i = 0; i < approx_set_traits<unsigned long long>::capacity; i++) {
+        if ((s & 1) != 0) {
+            if (first) {
+                first = false;
+            }
+            else {
+                out << ", ";
+            }
+            out << i;
+        }
+        s = s >> 1;
+    }
+    out << "}";
+}
+
+unsigned approx_set::size() const {
+    unsigned long long  tmp = m_set;
+    unsigned r = 0;
+    while (tmp > 0) {
+        if ((tmp & 1) != 0) {
+            r++;
+        }
+        tmp = tmp >> 1;
+    }
+    return r;
+}
+