Remove non-0.5.0 warning for emit keyword (make it mandatory)

test/libsolidity/syntaxTests/nameAndTypeResolution/080_event.sol

@@ -1,6 +1,5 @@
 contract c {
     event e(uint indexed a, bytes3 indexed s, bool indexed b);
-    function f() public { e(2, "abc", true); }
+    function f() public { emit e(2, "abc", true); }
 }
 // ----
-// Warning: (102-119): Invoking events without "emit" prefix is deprecated.

test/libsolidity/syntaxTests/nameAndTypeResolution/090_event_call.sol

@@ -1,6 +1,5 @@
 contract c {
     event e(uint a, bytes3 indexed s, bool indexed b);
-    function f() public { e(2, "abc", true); }
+    function f() public { emit e(2, "abc", true); }
 }
 // ----
-// Warning: (94-111): Invoking events without "emit" prefix is deprecated.

test/libsolidity/syntaxTests/nameAndTypeResolution/094_event_inheritance.sol

@@ -2,7 +2,6 @@ contract base {
     event e(uint a, bytes3 indexed s, bool indexed b);
 }
 contract c is base {
-    function f() public { e(2, "abc", true); }
+    function f() public { emit e(2, "abc", true); }
 }
 // ----
-// Warning: (120-137): Invoking events without "emit" prefix is deprecated.

test/libsolidity/syntaxTests/nameAndTypeResolution/563_event_without_emit_deprecated.sol

@@ -5,4 +5,4 @@ contract C {
     }
 }
 // ----
-// Warning: (62-65): Invoking events without "emit" prefix is deprecated.
+// TypeError: (62-65): Event invocations have to be prefixed by "emit".

test/libsolidity/syntaxTests/types/empty_tuple_event.sol

@@ -2,9 +2,9 @@ pragma solidity ^0.4.3;
 contract C {
     event SomeEvent();
     function a() public {
-        (SomeEvent(), 7);
+        (emit SomeEvent(), 7);
     }
 }
 // ----
-// Warning: (95-106): Invoking events without "emit" prefix is deprecated.
+// TypeError: (95-106): Event invocations have to be prefixed by "emit".
 // Warning: (95-106): Tuple component cannot be empty.

test/libsolidity/syntaxTests/types/empty_tuple_event_050.sol

@@ -1,10 +0,0 @@
-pragma experimental "v0.5.0";
-contract C {
-    event SomeEvent();
-    function a() public {
-        (SomeEvent(), 7);
-    }
-}
-// ----
-// TypeError: (101-112): Event invocations have to be prefixed by "emit".
-// TypeError: (101-112): Tuple component cannot be empty.