Sort tests.

test/libsolidity/semanticTests/functionCall/external_function.sol

@@ -0,0 +1,18 @@
+contract c {
+    function f(uint256 a) public returns (uint256) {
+        return a;
+    }
+
+    function test(uint256 a, uint256 b)
+        external
+        returns (uint256 r_a, uint256 r_b)
+    {
+        r_a = f(a + 7);
+        r_b = b;
+    }
+}
+
+// ====
+// compileViaYul: also
+// ----
+// test(uint256,uint256): 2, 3 -> 9, 3