Jin Yao reported issue with possible conflict between raw events and
term values in pmu event syntax.

Currently following syntax is resolved as raw event with 0xead value:

  uncore_imc_free_running/read/

instead of using 'read' term from uncore_imc_free_running pmu, because
'read' is correct raw event syntax with 0xead value.

To solve this issue we do following:

  - check existing terms during rXXXX syntax processing
    and make them priority in case of conflict

  - allow pmu/r0x1234/ syntax to be able to specify conflicting
    raw event (implemented in previous patch)

Also add automated tests for this and perf_pmu__parse_cleanup call to
parse_events_terms, so the test gets properly cleaned up.

Fixes: 3a6c51e4 ("perf parser: Add support to specify rXXX event with pmu")
Reported-by: Jin Yao <yao.jin@linux.intel.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Jin Yao <yao.jin@linux.intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20200726075244.1191481-2-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>