[SMTChecker] Added support for public getters through this.

test/libsolidity/smtCheckerTests/functions/getters/struct_2.sol

@@ -0,0 +1,19 @@
+pragma experimental SMTChecker;
+//pragma abicoder v2;
+
+contract C {
+	struct S {
+		uint[2] a;
+		uint u;
+	}
+
+	S public s;
+
+	function f() public view {
+		uint u = this.s();
+		assert(u == s.u); // should hold
+		assert(u == 1); // should fail
+	}
+}
+// ----
+// Warning 6328: (207-221): CHC: Assertion violation happens here.