These are benign but worth fixing as it clears the log to find more important errors.
A common problem with the sanitizer is that enums are often used to represent bits (e.g. 1, 2, 4, 8 etc) but without specifying the enum type, the compiler is free to use unsigned or signed int. In this case it uses int, and when it performs bitwise operations on the int type, the sanitizer complains.
This is probably because a bitshift with negative signed value can give undefined behaviour - the sanitizer can't know ahead of time that you are using the enum for sensible bitflags.