After updating to AS 7.0.1417 a project was compiled with no errors, but a warning '"LITTLE_ENDIAN" redefined' appeared. The first definition was in line 217 of file:
C:\Program Files (x86)\Atmel\Studio\7.0\Packs\atmel\SAMD21_DFP\1.2.276\samd21a\include\samd21g18a.h
The redefinition was in line 17 of file:
c:\program files (x86)\atmel\studio\7.0\toolchain\arm\arm-gnu-toolchain\arm-none-eabi\include\machine\endian.h
Looking at this file it looks like the symbol __BSD_VISIBLE is defined somewhere, but where?