Merge pull request #9706 from ethereum/smt_fix_tuple_lvalue

[SMTChecker] Fix unary operator on lvalue tuple

test/libsolidity/smtCheckerTests/operators/unary_operators_tuple_1.sol

@@ -0,0 +1,11 @@
+pragma experimental SMTChecker;
+contract C {
+	function f(bool b) public pure {
+		uint x;
+		if (b) ++(x);
+		if (b) --(x);
+		if (b) delete(b);
+		assert(x == 0);
+		assert(!b);
+	}
+}

test/libsolidity/smtCheckerTests/operators/unary_operators_tuple_2.sol

@@ -0,0 +1,11 @@
+pragma experimental SMTChecker;
+contract C {
+	function f(bool b) public pure {
+		uint x;
+		if (b) ++((((((x))))));
+		if (b) --((((((x))))));
+		if (b) delete((((((b))))));
+		assert(x == 0);
+		assert(!b);
+	}
+}

test/libsolidity/smtCheckerTests/operators/unary_operators_tuple_3.sol

@@ -0,0 +1,12 @@
+pragma experimental SMTChecker;
+contract C {
+	function f(bool b) public pure {
+		uint x;
+		if (b) ++(x);
+		else x += 1;
+		assert(x == 1);
+		assert(!b);
+	}
+}
+// ----
+// Warning 6328: (140-150): Assertion violation happens here