Add ABIEncoderV2 cleanup tests.

test/libsolidity/semanticTests/abiEncoderV2/cleanup/bool.sol

@@ -0,0 +1,21 @@
+pragma experimental ABIEncoderV2;
+
+contract C {
+    function gggg(bool x) external pure returns (bool) {
+        return x;
+    }
+    function f(uint256 a) external view returns (bool) {
+        bool x = false;
+        assembly { x := a }
+        return this.gggg(x);
+    }
+}
+// ----
+// f(uint256): 0 -> false
+// gggg(bool): 0 -> false # test validation as well as sanity check #
+// f(uint256): 1 -> true
+// gggg(bool): 1 -> true
+// f(uint256): 2 -> true
+// gggg(bool): 2 -> FAILURE
+// f(uint256): 0x1000 -> true
+// gggg(bool): 0x1000 -> FAILURE