I have no idea what this function does based on its name. It is inherited from C, so should at least mention that name in its documentation, but I believe we should find a better name.
The documentation says:
Multiply by an integer power of 2. Returns x * 2**n.
I'm at a loss for how to rename this function, though. Michael says this is useful for recombining a mantissa and an exponent and so is useful for low-level float manipulation, maybe that can help with finding a new name? Very open to suggestions.