The next cset needs to compare if a flex version is greater or
equal/less than another, but since there is no canonical, generally
available way to compare versions in the command line (sort -V, yeah,
but...), just use awk to canonicalize the versions like is also done in
scripts/rust_is_available.sh.

There was a problem spotted in linux-next where a bashism, here
documents, aka the '<<<' stdin redirector, for strings to be used as the
stdin for awk. Use $(shell echo | awk ...) instead.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

$(or ...) is available since GNU Make 3.81, and useful to shorten the
code in some places.

Covert as follows:

  $(if A,A,B)  -->  $(or A,B)

This patch also converts:

  $(if A, A, B) --> $(or A, B)

Strictly speaking, the latter is not an equivalent conversion because
GNU Make keeps spaces after commas; if A is not empty, $(if A, A, B)
expands to " A", while $(or A, B) expands to "A".

Anyway, preceding spaces are not significant in the code hunks I touched.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

As it is used by several other tools, better move it outside tools/perf.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-34s9kue3xq9w5mijdmfrfx8s@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>