The SVD for STM32L4x1,4x2 contains a USB_SRAM "peripheral", and a USB_FS peripheral which derives from the USB_SRAM peripheral. Unfortunately this isn't correct: USB_FS should have all the registers inside USB_SRAM (RM0394 43.6.1), and USB_SRAM should have a collection of different registers (RM0394 43.6.2). However, the USB_SRAM really is just a big block of memory, and isn't strictly partitioned into registers -- it's more a set of descriptors which can start at any offset.

So the SVD should really contain USB_FS with all the registers currently in USB_SRAM, and USB_SRAM should cease to exist at all, or at least be a peripheral with no registers.