Handle fork in target application (#191)

* Always print PID in log messages

* omnitrace-dl updates

- omnitrace_preload does not call omnitrace_init or omnitrace_init_tooling
- omnitrace_preload will call omnitrace_set_mpi if OMNITRACE_USE_MPI
  or OMNITRACE_USE_MPIP in the env is true but not call it otherwise
  because doing so either overrides OMNITRACE_USE_PID (when true) or
  disable mpip from initialization (when false) and the MPI
  init can be caught later and override OMNITRACE_USE_PID

* config updates

- set_setting_value sets user update type
- remove volatile from get_settings_configured
- don't override settings::default_process_suffix
- don't kill process in omnitrace_exit_action
- set_state ignores updating state if >= State::Finalized

* Handle state > State::Finalized

* fork gotcha updates

- unsets LD_PRELOAD
- sets OMNITRACE_ROOT_PROCESS
- sets OMNITRACE_CHILD_PROCESS

* libomnitrace library.cpp updates

- basic_bundle for fini metrics
- handle finalization from child process

* sampling updates

- sampling::shutdown handles when child process

* Add example and test using fork

* Update run-ci script to support not submitting

* Tweak test envs

* Update build flags when codecov enabled

* remove unnecessary includes of sampling header

* Replace mpi copy/fini static lambda with free-funcs

* Update codecov job

* Fix OMPT segfaults after finalization

* Miscellaneous updates after rebase

* fixes for causal profiling

* revert some run-ci.sh changes

* Disable storing env in sampling::shutdown

* formatting fix

* Update timemory submodule

- fixed occasional synchronization issues with allocator offloading
- exclude protozero:: from internal samples

* improve root/child process detection

- avoid omnitrace_finalize in MPI when child process
- revert some testing tweaks

tests/CMakeLists.txt

@@ -810,6 +810,13 @@ omnitrace_add_validation_test(
          0
          -p)
 
+omnitrace_add_test(
+    NAME fork
+    TARGET fork-example
+    REWRITE_ARGS -e -v 2 --print-instrumented modules -i 16
+    RUNTIME_ARGS -e -v 1 --label file -i 16
+    ENVIRONMENT "${_base_environment};OMNITRACE_CRITICAL_TRACE=ON")
+
 # -------------------------------------------------------------------------------------- #
 #
 # critical-trace tests
@@ -846,7 +853,6 @@ set(_parallel_overhead_critical_trace_environ
     "OMNITRACE_OUTPUT_PREFIX=parallel-overhead-critical-trace/"
     "OMNITRACE_CRITICAL_TRACE_DEBUG=ON"
     "OMNITRACE_VERBOSE=4"
-    "OMNITRACE_DEBUG=ON"
     "OMNITRACE_USE_PID=OFF"
     "OMNITRACE_TIME_OUTPUT=OFF")