Finishes external call implementation.

test/libsolidity/semanticTests/array/memory.sol

@@ -0,0 +1,17 @@
+pragma solidity >= 0.6.0;
+
+contract C {
+    function h(uint[4] memory n) public pure returns (uint) {
+        return n[0] + n[1] + n[2] + n[3];
+    }
+
+    function i(uint[4] memory n) public view returns (uint) {
+        return this.h(n) * 2;
+    }
+}
+
+// ====
+// compileViaYul: also
+// ----
+// h(uint256[4]): 1, 2, 3, 4 -> 10
+// i(uint256[4]): 1, 2, 3, 4 -> 20