[SMTChecker] Added support for public getters through this.

test/libsolidity/smtCheckerTests/functions/getters/function.sol

@@ -0,0 +1,19 @@
+pragma experimental SMTChecker;
+
+contract C {
+	function () external returns (uint) public g;
+
+	function f() public {
+		g = this.X;
+		function () external returns (uint) e = this.g();
+		assert(e() == g()); // should hold, but fails because of the lack of support for tracking function pointers
+		assert(e() == 1); // should fail
+	}
+
+	function X() public pure returns (uint) {
+		return 42;
+	}
+}
+// ----
+// Warning 6328: (185-203): CHC: Assertion violation happens here.
+// Warning 6328: (295-311): CHC: Assertion violation happens here.