new free function tests

test/libsolidity/smtCheckerTests/file_level/struct.sol

@@ -0,0 +1,27 @@
+struct S {
+	uint x;
+	uint[] a;
+}
+
+function allocate(uint _x, uint _f) pure returns (S memory) {
+	S memory s;
+	s.x = _x;
+	s.a = new uint[](1);
+	s.a[0] = _f;
+	return s;
+}
+
+contract C {
+	function f() public pure {
+		S memory s = allocate(2, 1);
+		assert(s.x == 2); // should hold
+		assert(s.a[0] == 1); // should hold
+		assert(s.x == 3); // should fail
+		assert(s.a[0] == 4); // should fail
+	}
+}
+// ====
+// SMTEngine: all
+// ----
+// Warning 6328: (317-333): CHC: Assertion violation happens here.\nCounterexample:\n\ns = {x: 2, a: [1]}\n\nTransaction trace:\nC.constructor()\nC.f()\n    allocate(2, 1) -- internal call
+// Warning 6328: (352-371): CHC: Assertion violation happens here.\nCounterexample:\n\ns = {x: 2, a: [1]}\n\nTransaction trace:\nC.constructor()\nC.f()\n    allocate(2, 1) -- internal call