Reset_Handler resets variables set by SystemInit()

[cpq]

The very detailed report was done for https://github.com/STMicroelectronics/cmsis_device_l4/issues/2 This issue is not present on some lines, e.g. F4. And present on the majority of others, like L4, G0, H7, etc. Please fix the order of initialisation - data/bss section first, then SystemInit(), second.