It seems Thomas didn't add these files in non-windows builds.
The files themselves are #ifdef'd so they won't actually be compiled, but they need to be added to the build.
I will do it later today.
For the time being do it yourselves, locally.
For autotools, edit src/src/Makefile.am and add crashhandler.cpp in the codeblocks_SOURCES list of files.
For the .cbp builds, add src/crashhandler.cpp|h in the codeblocks-unix.cbp.