Tests for suffixes used to define operators

test/libsolidity/semanticTests/operators/userDefined/literal_suffix_as_operator_definition.sol

@@ -0,0 +1,24 @@
+type B is bool;
+using {bitnot as ~, bitor as |} for B global;
+
+// NOTE: There are no literals of type B so these cannot be actually used on anything
+function bitnot(B x) pure suffix returns (B) {
+    return B.wrap(!B.unwrap(x));
+}
+
+function bitor(B x, B y) pure suffix returns (B) {
+    return B.wrap(B.unwrap(x) || B.unwrap(y));
+}
+
+contract C {
+    function testBinary() pure public returns (B) {
+        B.wrap(true) | B.wrap(false);
+    }
+
+    function testUnary() pure public returns (B) {
+        -B.wrap(true);
+    }
+}
+// ----
+// testUnary() -> true
+// testBinary() -> false

test/libsolidity/syntaxTests/operators/userDefined/implementing_operator_with_literal_suffix_on_udvt.sol

@@ -0,0 +1,10 @@
+type Int is int;
+using {add as +, unsub as -} for Int global;
+
+function add(Int x, Int y) pure suffix returns (Int) {
+    return Int.wrap(Int.unwrap(x) + Int.unwrap(y));
+}
+
+function unsub(Int x) pure suffix returns (Int) {
+    return Int.wrap(-Int.unwrap(x));
+}

test/libsolidity/syntaxTests/operators/userDefined/implementing_operator_with_literal_suffix_on_value_type.sol

@@ -0,0 +1,13 @@
+using {add as +, unsub as -} for uint global;
+
+function add(uint x, uint y) pure suffix returns (uint) {
+    return x + y;
+}
+
+function unsub(uint x) pure suffix returns (uint) {
+    return uint(-int(x));
+}
+// ----
+// TypeError 8841: (0-45): Can only use "global" with user-defined types.
+// TypeError 5332: (7-10): Operators can only be implemented for user-defined value types.
+// TypeError 5332: (17-22): Operators can only be implemented for user-defined value types.