Disallow using modifiers not in the current contract or in base contracts.

test/libsolidity/syntaxTests/modifiers/access_in_library.sol

@@ -0,0 +1,9 @@
+library L {
+    modifier m() { _; }
+}
+contract C {
+    function f() L.m public {
+    }
+}
+// ----
+// TypeError 9428: (68-71): Can only use modifiers defined in the current contract or in base contracts.

test/libsolidity/syntaxTests/modifiers/cross_contract_access.sol

@@ -0,0 +1,9 @@
+contract C {
+    modifier m() { _; }
+}
+contract D {
+    function f() C.m public {
+    }
+}
+// ----
+// TypeError 9428: (69-72): Can only use modifiers defined in the current contract or in base contracts.

test/libsolidity/syntaxTests/modifiers/cross_contract_base.sol

@@ -0,0 +1,8 @@
+contract C {
+    modifier m() { _; }
+}
+contract D is C {
+    function f() C.m public {
+    }
+}
+// ----

test/libsolidity/syntaxTests/modifiers/cross_contract_unrelated.sol

@@ -0,0 +1,11 @@
+contract A {}
+contract C is A {
+    modifier m() { _; }
+}
+contract D is A {
+    function f() C.m public {
+    }
+}
+contract T is D, C {}
+// ----
+// TypeError 9428: (93-96): Can only use modifiers defined in the current contract or in base contracts.

test/libsolidity/syntaxTests/modifiers/library_via_using.sol

@@ -0,0 +1,10 @@
+library L {
+    modifier m() { _; }
+}
+contract C {
+    using L for *;
+    function f() L.m public {
+    }
+}
+// ----
+// TypeError 9428: (87-90): Can only use modifiers defined in the current contract or in base contracts.