Sort tests.

test/libsolidity/semanticTests/virtualFunctions/virtual_function_calls.sol

@@ -0,0 +1,22 @@
+contract Base {
+    function f() public returns (uint256 i) {
+        return g();
+    }
+
+    function g() public virtual returns (uint256 i) {
+        return 1;
+    }
+}
+
+
+contract Derived is Base {
+    function g() public override returns (uint256 i) {
+        return 2;
+    }
+}
+
+// ====
+// compileViaYul: also
+// ----
+// g() -> 2
+// f() -> 2