perf check: Add libLLVM feature

Advertise when perf is built with the HAVE_LIBLLVM_SUPPORT option.

Committer testing:

  $ perf -vv | grep LLVM
               libLLVM: [ on  ]  # HAVE_LIBLLVM_SUPPORT
  $

And the form to use in scripts, notably the tools/perf/tests/shell/
'perf test' ones:

  $ perf check feature libllvm
               libLLVM: [ on  ]  # HAVE_LIBLLVM_SUPPORT
  $ perf check -q feature libllvm && echo LLVM is present
  LLVM is present
  $ perf check -q feature liballvm && echo ALLVM is present
  $

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.ibm.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Charlie Jenkins <charlie@rivosinc.com>
Cc: Collin Funk <collin.funk1@gmail.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Dr. David Alan Gilbert <linux@treblig.org>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Haibo Xu <haibo1.xu@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Li Huafei <lihuafei1@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <nick.desaulniers+lkml@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-check.txt

@@ -56,6 +56,7 @@ feature::
                 libcapstone             /  HAVE_LIBCAPSTONE_SUPPORT
                 libdw-dwarf-unwind      /  HAVE_LIBDW_SUPPORT
                 libelf                  /  HAVE_LIBELF_SUPPORT
+                libLLVM                 /  HAVE_LIBLLVM_SUPPORT
                 libnuma                 /  HAVE_LIBNUMA_SUPPORT
                 libopencsd              /  HAVE_CSTRACE_SUPPORT
                 libperl                 /  HAVE_LIBPERL_SUPPORT

tools/perf/builtin-check.c

@@ -48,6 +48,7 @@ struct feature_status supported_features[] = {
 	FEATURE_STATUS("libcapstone", HAVE_LIBCAPSTONE_SUPPORT),
 	FEATURE_STATUS("libdw-dwarf-unwind", HAVE_LIBDW_SUPPORT),
 	FEATURE_STATUS("libelf", HAVE_LIBELF_SUPPORT),
+	FEATURE_STATUS("libLLVM", HAVE_LIBLLVM_SUPPORT),
 	FEATURE_STATUS("libnuma", HAVE_LIBNUMA_SUPPORT),
 	FEATURE_STATUS("libopencsd", HAVE_CSTRACE_SUPPORT),
 	FEATURE_STATUS_TIP("libperl", HAVE_LIBPERL_SUPPORT, "Deprecated, use LIBPERL=1 and install perl-ExtUtils-Embed/libperl-dev to build with it"),