gcc -dM -E test.cor
g++ -dM -E test.cpp
It appears that resource limits (which include the maximum size of a core dump file) are set by PAM on login. The settings for these limits are in /etc/security/limits.conf, which on my system (which is unmodified) is comments only. A quick look at the source code suggests that the default core dump limit is 0 (zero), which means no dump at all is created (even though the message suggests otherwise).
In summary: edit /etc/security/limits.conf, set the core limit to be non-zero (measured in kilobytes), and log in again.
I hope that works!
autocmd BufNewFile,BufRead,BufEnter *.cpp,*.hpp set omnifunc=omni#cpp#complete#Main
map <C-F12> :!ctags -R --c++-kinds=+p --fields=+iaS --extra=+q .<CR>
imap <C-Space> <C-x><C-o>
let OmniCpp_MayCompleteDot = 0
let OmniCpp_MayCompleteArrow = 0
"/usr/bin/xvkbd -xsendevent -text "\[Return]""
m:0x0 + b:8
"/usr/bin/xvkbd -xsendevent -text "\[Alt]\[Left]""
m:0x0 + b:7
"/usr/bin/xvkbd -xsendevent -text "\[Alt]\[Right]""
m:0x0 + b:6