Add CLI and JSON option to select SMTChecker targets

test/cmdlineTests/model_checker_targets_assert_chc/args

@@ -0,0 +1 @@
+--model-checker-engine chc --model-checker-targets assert

test/cmdlineTests/model_checker_targets_assert_chc/err

@@ -0,0 +1,14 @@
+Warning: CHC: Assertion violation happens here.
+Counterexample:
+arr = []
+a = 0
+x = 0
+
+Transaction trace:
+test.constructor()
+State: arr = []
+test.f(0, 1)
+  --> model_checker_targets_assert_chc/input.sol:12:3:
+   |
+12 | 		assert(x > 0);
+   | 		^^^^^^^^^^^^^

test/cmdlineTests/model_checker_targets_assert_chc/input.sol

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+pragma experimental SMTChecker;
+contract test {
+	uint[] arr;
+    function f(address payable a, uint x) public {
+		require(x >= 0);
+		--x;
+		x + type(uint).max;
+		2 / x;
+		a.transfer(x);
+		assert(x > 0);
+		arr.pop();
+    }
+}