For bit_set, allow + and - to be aliases for | and &~, respectively

src/ir.cpp

@@ -4621,6 +4621,15 @@ irValue *ir_emit_arith(irProcedure *proc, TokenKind op, irValue *left, irValue *
 	}
 
 handle_op:
+
+	// NOTE(bill): Bit Set Aliases for + and -
+	if (is_type_bit_set(type)) {
+		switch (op) {
+		case Token_Add: op = Token_Or;     break;
+		case Token_Sub: op = Token_AndNot; break;
+		}
+	}
+
 	switch (op) {
 	case Token_Shl:
 		{