Adding more syntax and semantic tests.

test/libsolidity/semanticTests/array/copying/array_copy_storage_storage_different_base_nested.sol

@@ -0,0 +1,25 @@
+contract c {
+    uint48[5][2] data1;
+    uint120[6][3] data2;
+
+    function test() public returns (uint256 x, uint120 y) {
+        data2[0][0] = 11;
+        data2[1][0] = 22;
+        data2[2][0] = 33;
+
+        data1[0][0] = 0;
+        data1[0][1] = 1;
+        data1[0][2] = 2;
+        data1[0][3] = 3;
+        data1[0][4] = 4;
+        data1[1][0] = 3;
+        data2 = data1;
+        assert(data1[0][1] == data2[0][1]);
+        x = data2.length;
+        y = data2[0][4];
+    }
+}
+// ====
+// compileViaYul: also
+// ----
+// test() -> 3, 4