Add CLI and JSON option to select SMTChecker targets

test/cmdlineTests/model_checker_targets_error/args

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+--model-checker-targets aaa,bbb

test/cmdlineTests/model_checker_targets_error/err

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+Invalid option for --model-checker-targets: aaa,bbb

test/cmdlineTests/model_checker_targets_error/exit

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+1

test/cmdlineTests/model_checker_targets_error/input.sol

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+// 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();
+    }
+}