Merge pull request #4378 from ethereum/noBaseWithoutArguments

[BREAKING] Disallow calling base constructors without arguments.

test/libsolidity/syntaxTests/inheritance/disallow_modifier_style_without_parentheses.sol

@@ -1,4 +1,4 @@
 contract A { constructor() public { } }
 contract B is A { constructor() A public {  } }
 // ----
-// Warning: (72-73): Modifier-style base constructor call without arguments.
+// DeclarationError: (72-73): Modifier-style base constructor call without arguments.

test/libsolidity/syntaxTests/inheritance/modifiers_in_constructor_context.sol

@@ -0,0 +1,9 @@
+// This generated an invalid warning on m1 in some compiler versions.
+contract A {
+  constructor() m1 public { }
+  modifier m1 { _; }
+}
+contract B is A {
+  modifier m2 { _; }
+  constructor() A() m1 m2 public {  }
+}