spatial_data.adb does not compile on gcc-11.3.0

[bib1963]

spatial_data.adb does compile on 10.2.0, but not on 11.3.0.

It barfs with:

   [Ada]          spatial_data.adb
/tmp/ccHCc73u.s: Assembler messages:
/tmp/ccHCc73u.s:14356: Error: bad immediate value for offset (4096)

This is on a RPi3 32bit, after having to change type Real18 is digits 18; to type Real18 is digits 15; in ./src/results/adabase-results.ads & ./src/miscellaneous/spatial_data.ads, which has always worked previously, at least for my workloads.

[bib1963]

Sigh... it builds on x86_64.