The cleanup in 185630085 removed some symbols that were previously
exported as public experimental API in Cogl 1.9.8. That release is
already well after the point where we were meant to freeze the ABI so
we probably shouldn't be breaking it again. This patch adds the
removed functions back in so that for 1.9.10 we won't have to bump the
soname. The symbols are bundled together in a new file called
cogl2-compatibility.c so that they will be easy to remove again after
we can break ABI. It is expected that we will revert this patch
immediately after branching for Cogl 1.10.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
