darwin: fix compilation errors with -DMURPHI=OFF -DGUI=OFF -DRX_PATH=

* hoard/heaplayers/threadheap.h, hoard/userealtls.cpp,
tools/probabilistic.cpp, wibble/empty.h, wibble/mixin.h,
wibble/range.h, wibble/singleton.h: here.
3 jobs for er/fix-macosx in 14 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
failed #39529
build-stable

00:00:08

failed #39528
build-unstable

00:00:05

failed #39527
build-stable

00:00:05

 
Name Stage Failure
failed
build-stable Build
Running with gitlab-runner 11.8.0 (4745a6f3)
on node7 48edbc67
Using Docker executor with image gadl/spot-debuild:stable ...
Pulling docker image gadl/spot-debuild:stable ...
ERROR: Job failed: Error response from daemon: pull access denied for gadl/spot-debuild, repository does not exist or may require 'docker login' (executor_docker.go:168:1s)
failed
build-unstable Build
Running with gitlab-runner 11.7.0 (8bb608ff)
on node13 e31ebb27
Using Docker executor with image gadl/spot-debuild ...
Pulling docker image gadl/spot-debuild ...
ERROR: Job failed: Error response from daemon: pull access denied for gadl/spot-debuild, repository does not exist or may require 'docker login' (executor_docker.go:168:1s)