Add syntax tests and Changelog entry

Changelog.md

@@ -1,7 +1,9 @@
 ### 0.5.0 (unreleased)
 
-Features:
+Breaking Changes:
+ * Type Checker: Disallow arithmetic operations for Boolean variables.
 
+Features:
 
 Bugfixes:
 

test/libsolidity/syntaxTests/types/bool_ops.sol

@@ -0,0 +1,53 @@
+contract C {
+    function f(bool a, bool b) public pure {
+        bool c;
+        // OK
+        c = !a;
+        c = !b;
+        c = a == b;
+        c = a != b;
+        c = a || b;
+        c = a && b;
+
+        // Not OK
+        c = a > b;
+        c = a < b;
+        c = a >= b;
+        c = a <= b;
+        c = a & b;
+        c = a | b;
+        c = a ^ b;
+        c = ~a;
+        c = ~b;
+        c = a + b;
+        c = a - b;
+        c = -a;
+        c = -b;
+        c = a * b;
+        c = a / b;
+        c = a ** b;
+        c = a % b;
+        c = a << b;
+        c = a >> b;
+    }
+}
+// ----
+// TypeError: (231-236): Operator > not compatible with types bool and bool
+// TypeError: (250-255): Operator < not compatible with types bool and bool
+// TypeError: (269-275): Operator >= not compatible with types bool and bool
+// TypeError: (289-295): Operator <= not compatible with types bool and bool
+// TypeError: (309-314): Operator & not compatible with types bool and bool
+// TypeError: (328-333): Operator | not compatible with types bool and bool
+// TypeError: (347-352): Operator ^ not compatible with types bool and bool
+// TypeError: (366-368): Unary operator ~ cannot be applied to type bool
+// TypeError: (382-384): Unary operator ~ cannot be applied to type bool
+// TypeError: (398-403): Operator + not compatible with types bool and bool
+// TypeError: (417-422): Operator - not compatible with types bool and bool
+// TypeError: (436-438): Unary operator - cannot be applied to type bool
+// TypeError: (452-454): Unary operator - cannot be applied to type bool
+// TypeError: (468-473): Operator * not compatible with types bool and bool
+// TypeError: (487-492): Operator / not compatible with types bool and bool
+// TypeError: (506-512): Operator ** not compatible with types bool and bool
+// TypeError: (526-531): Operator % not compatible with types bool and bool
+// TypeError: (545-551): Operator << not compatible with types bool and bool
+// TypeError: (565-571): Operator >> not compatible with types bool and bool