It's a 38k source file, which makes it MUCH smaller than other generated
files like qlocale_data_p.h (982k) and qunicodetables.cpp (718k). The
constants are platform-independent, since they are defined by IEEE 754,
so they will never change.

The generator tool is moved to util/ and removed from the build. That's
one fewer bootstrapped tool to have to worry about.

The output file is committed as .cpp so it won't get installed.

Fixes: QTBUG-76165
Change-Id: I2b1955a995ad40f3b89afffd15a3ded58dc3e35f
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>