Desugar bitwise negation into XOR and kill all UnaryOp stuff.

src/parser.cc

Index: src/parser.cc
diff --git a/src/parser.cc b/src/parser.cc
index aa83969e99977ac61b9e12adc5427a74ff8c0851..4947790395f3c431db7ef1ef68f30d47fccb8e5b 100644
--- a/src/parser.cc
+++ b/src/parser.cc
@@ -3204,6 +3204,13 @@ Expression* Parser::ParseUnaryExpression(bool* ok) {
                                            factory()->NewNumberLiteral(-1),
                                            position);
     }
+    // ...and one more time for '~foo' => 'foo^(~0)'.
+    if (op == Token::BIT_NOT) {
+      return factory()->NewBinaryOperation(Token::BIT_XOR,
+                                           expression,
+                                           factory()->NewNumberLiteral(~0),
+                                           position);
+    }
 
     return factory()->NewUnaryOperation(op, expression, position);