[SMTChecker] Fix ICE in BMC function inlining

test/libsolidity/smtCheckerTests/functions/function_external_call_should_not_inline_1.sol

@@ -0,0 +1,16 @@
+pragma experimental SMTChecker;
+contract State {
+	C c;
+	function f() public returns (uint) {
+		while(true)
+			c.setOwner();
+	}
+}
+contract C {
+	address owner;
+	function setOwner() public {
+		owner = address(0);
+	}
+}
+// ----
+// Warning 5084: (198-208): Type conversion is not yet fully supported and might yield false positives.

test/libsolidity/smtCheckerTests/functions/function_external_call_should_not_inline_2.sol

@@ -0,0 +1,16 @@
+pragma experimental SMTChecker;
+contract Other {
+	C c;
+	function h(bool b) public {
+		if (b)
+			c.setOwner(address(0));
+	}
+}
+contract C {
+	address owner;
+	function setOwner(address _owner) public {
+		owner = _owner;
+	}
+}
+// ----
+// Warning 5084: (107-117): Type conversion is not yet fully supported and might yield false positives.