* gnu/packages/patches/rct-add-missing-headers.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/cpp.scm (rct): Use the patch, enable RTTI.
[source]: Use the patch to add missing headers from installation.
[arguments]: Enable RTTI in configure-flags.
Signed-off-by: Ludovic Courtès <ludo@gnu.org>
