This commit adds initial support for LTTng.
When --enable-lttng=no or is not specified, no tracing code is included.
When --enable-lttng=yes, LTTng tracing events are (will be) generated.
configure.ac:
- add --enable-lttng
- define HAVE_LTTNG when enabled
- minimum LTTng version: 2.12.0
lib:
- add trace.[ch]
- update subdir.am
Signed-off-by: Quentin Young <qlyoung@nvidia.com>