Turns it into warning (error for 0.5.0) and adds Changelog entry.

test/libsolidity/syntaxTests/types/empty_tuple_event.sol

@@ -7,4 +7,4 @@ contract C {
 }
 // ----
 // Warning: (95-106): Invoking events without "emit" prefix is deprecated.
-// TypeError: (95-106): Type of tuple component cannot be null.
+// Warning: (95-106): Tuple component cannot be empty.

test/libsolidity/syntaxTests/types/empty_tuple_event_050.sol

@@ -7,4 +7,4 @@ contract C {
 }
 // ----
 // TypeError: (101-112): Event invocations have to be prefixed by "emit".
-// TypeError: (101-112): Type of tuple component cannot be null.
+// TypeError: (101-112): Tuple component cannot be empty.

test/libsolidity/syntaxTests/types/empty_tuple_function.sol

@@ -1,11 +1,12 @@
 pragma solidity ^0.4.3;
 contract C {
-    function f() {}
-    function a() public {
+    function f() private pure {}
+    function a() public pure {
         bool x = true;
         bool y = true;
         (x) ? (f(), y = false) : (f(), y = false);
     }
 }
 // ----
-// TypeError: (144-147): Type of tuple component cannot be null.
+// Warning: (162-165): Tuple component cannot be empty.
+// Warning: (181-184): Tuple component cannot be empty.

test/libsolidity/syntaxTests/types/empty_tuple_function_050.sol

@@ -0,0 +1,11 @@
+pragma experimental "v0.5.0";
+contract C {
+    function f() private pure {}
+    function a() public pure {
+        bool x = true;
+        bool y = true;
+        (x) ? (f(), y = false) : (f(), y = false);
+    }
+}
+// ----
+// TypeError: (168-171): Tuple component cannot be empty.

test/libsolidity/syntaxTests/types/empty_tuple_function_self.sol

@@ -1,8 +0,0 @@
-pragma solidity ^0.4.3;
-contract C {
-    function a() public {
-        (a(), 7);
-    }
-}
-// ----
-// TypeError: (72-75): Type of tuple component cannot be null.

test/libsolidity/syntaxTests/types/empty_tuple_lvalue.sol

@@ -1,6 +1,6 @@
 pragma solidity ^0.4.3;
 contract C {
-    function f() public pure {}
+    function f() private pure {}
     function a() public {
         uint x;
         uint y;
@@ -8,4 +8,6 @@ contract C {
     }
 }
 // ----
-// TypeError: (145-148): Type of tuple component cannot be null.
+// Warning: (146-149): Tuple component cannot be empty.
+// Warning: (151-154): Tuple component cannot be empty.
+// TypeError: (145-155): Type tuple(tuple(),tuple()) is not implicitly convertible to expected type tuple(uint256,uint256).

test/libsolidity/syntaxTests/types/empty_tuple_lvalue_050.sol

@@ -0,0 +1,11 @@
+pragma experimental "v0.5.0";
+contract C {
+    function f() private pure {}
+    function a() public {
+        uint x;
+        uint y;
+        (x, y) = (f(), f());
+    }
+}
+// ----
+// TypeError: (152-155): Tuple component cannot be empty.

test/libsolidity/syntaxTests/types/empty_tuple_lvalue_array.sol

@@ -0,0 +1,13 @@
+pragma solidity ^0.4.3;
+contract C {
+    function f() private pure {}
+    function a() public {
+        uint x;
+        uint y;
+        (x, y) = [f(), f()];
+    }
+}
+// ----
+// Warning: (146-149): Tuple component cannot be empty.
+// Warning: (151-154): Tuple component cannot be empty.
+// TypeError: (145-155): Type tuple()[2] memory is not implicitly convertible to expected type tuple(uint256,uint256).