Buildroot compiling in Ubuntu 20.04 with qt5.15.2 and gcc11

[Hoytash]

I ran into many errors when compiling the powertune image with Ubuntu 20.04, but i have found a workaround to share, the error was giving

error: 'numerical_limits' is not a class template 300 | class numeric_limits <QR_PREPEND_NAMESPACE(qfloat16). : public numeric_limits

I found by adding the 3 lines

#ifdef __cplusplus
#include
#endif

to the files qfloat16.h and qbytearraymatcher.h

fixed this issue incase anyone else was having the same