Implement bit operations.

test/libsolidity/semanticTests/expressions/bit_operators.sol

@@ -0,0 +1,19 @@
+contract test {
+    uint8 x;
+    uint v;
+    function f() public returns (uint x, uint y, uint z) {
+        uint16 a;
+        uint32 b;
+        assembly {
+            a := 0x0f0f0f0f0f
+            b := 0xff0fff0fff
+        }
+        x = a & b;
+        y = a | b;
+        z = a ^ b;
+    }
+}
+// ====
+// compileViaYul: also
+// ----
+// f() -> 3855, 268374015, 268370160