save some log structure flash when features disabled

[tridge]

this continues some work that @peterbarker has started. I ran across one of these while working on a different PR

[peterbarker]

../../libraries/AC_Avoidance/AC_Avoidance_Logging.cpp: In member function 'void AP_OABendyRuler::Write_OABendyRuler(uint8_t, bool, float, float, bool, float, const Location&, const Location&) const':
../../libraries/AC_Avoidance/AC_Avoidance_Logging.cpp:23:46: error: 'ahrs' is not a member of 'AP'
   23 |         yaw         : (uint16_t)wrap_360(AP::ahrs().yaw_sensor * 0.01f),
      |                                              ^~~~

... that was the first error which popped up; consider using ./Tools/autotest/test_build_options.py with --define-match-glob to see if it picks up the others.

[peterbarker]

I'd prefer to put the positive case first - ie. don't negate this and put the empty case at the end.

Not all that fussed, mind you.

[tridge]

... that was the first error which popped up; consider using ./Tools/autotest/test_build_options.py with --define-match-glob to see if it picks up the others.

ok, thanks. Started a run with "--define-match-glob=AP*" - does that sound right?

[tridge]

../../libraries/AC_Avoidance/AC_Avoidance_Logging.cpp: In member function 'void AP_OABendyRuler::Write_OABendyRuler(uint8_t, bool, float, float, bool, float, const Location&, const Location&) const':
../../libraries/AC_Avoidance/AC_Avoidance_Logging.cpp:23:46: error: 'ahrs' is not a member of 'AP'
23 | yaw : (uint16_t)wrap_360(AP::ahrs().yaw_sensor * 0.01f),
| ^~~~

that error also happens with master, it doesn't have anything to do with this PR
ie. this configure:

./waf configure --disable-AC_AVOID --disable-MODE_FOLLOW

produces:

../../libraries/AC_Avoidance/AC_Avoidance_Logging.cpp: In member function ‘void AP_OABendyRuler::Write_OABendyRuler(uint
8_t, bool, float, float, bool, float, const Location&, const Location&) const’:
../../libraries/AC_Avoidance/AC_Avoidance_Logging.cpp:23:46: error: ‘ahrs’ is not a member of ‘AP’
   23 |         yaw         : (uint16_t)wrap_360(AP::ahrs().yaw_sensor * 0.01f),
      |                                              ^~~~

[peterbarker]

... that was the first error which popped up; consider using ./Tools/autotest/test_build_options.py with --define-match-glob to see if it picks up the others.

ok, thanks. Started a run with "--define-match-glob=AP*" - does that sound right?

Nope, --define-match-glob=AP_AVOIDANCE_ENABLED as that's the define in play in this PR