u_trace: add support for indirect data

Allows a driver to declare indirect arguments for its tracepoints and
pass an address. u_trace will request a copy of the data which should
be implemented on the command processor.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Co-Authored-by: Danylo Piliaiev <dpiliaiev@igalia.com>
Reviewed-by: Danylo Piliaiev <dpiliaiev@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/29944>

src/util/tests/perf/u_trace_test.cpp

@@ -11,7 +11,8 @@ static int
 test_thread(void *_state)
 {
    struct u_trace_context ctx = {};
-   u_trace_context_init(&ctx, NULL, NULL, NULL, NULL, NULL, NULL);
+   u_trace_context_init(&ctx, NULL, 8, 0, NULL, NULL, NULL,
+                        NULL, NULL, NULL, NULL);
    u_trace_context_fini(&ctx);
 
    return 0;