[SMTChecker] User timeout option

test/cmdlineTests/model_checker_timeout_chc/args

@@ -0,0 +1 @@
+--model-checker-engine chc --model-checker-timeout 1

test/cmdlineTests/model_checker_timeout_chc/err

@@ -0,0 +1,17 @@
+Warning: CHC: Assertion violation might happen here.
+ --> model_checker_timeout_chc/input.sol:6:3:
+  |
+6 | 		assert(x > 0);
+  | 		^^^^^^^^^^^^^
+
+Warning: CHC: Assertion violation might happen here.
+ --> model_checker_timeout_chc/input.sol:7:3:
+  |
+7 | 		assert(x > 2);
+  | 		^^^^^^^^^^^^^
+
+Warning: CHC: Assertion violation might happen here.
+ --> model_checker_timeout_chc/input.sol:8:3:
+  |
+8 | 		assert(x > 4);
+  | 		^^^^^^^^^^^^^

test/cmdlineTests/model_checker_timeout_chc/input.sol

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+pragma experimental SMTChecker;
+contract test {
+    function f(uint x) public pure {
+		assert(x > 0);
+		assert(x > 2);
+		assert(x > 4);
+    }
+}