New test.

From-SVN: r73581

gcc/testsuite/g++.dg/eh/dtor2.C

+// PR c++/12751
+// tree-ssa eh lowering bug ran a destructor twice for one object
+// { dg-do run }
+
+static int check;
+
+struct Y {
+  Y();
+  ~Y();
+};
+
+void foo() {
+  Y y1;
+  Y y2;
+  switch(0) {
+    case 1: {
+        Y y3;
+        return;
+      }
+  }
+}
+
+Y::Y() { ++check; }
+Y::~Y() { --check; }
+
+int main()
+{
+  foo ();
+  return check;
+}