perf evsel: Add lazy-initialized probe type detection helpers

perf evsel: Add lazy-initialized probe type detection helpers

Several places in perf need to check whether an evsel is a kprobe or
uprobe, which requires looking up the PMU by name via evsel__find_pmu().
This lookup walks the PMU list each time, which is wasteful when the
same evsel is checked repeatedly.

Add evsel__is_kprobe(), evsel__is_uprobe(), and evsel__is_probe() that
resolve the probe type on first call via evsel__pmu_name() and cache
the result in a 3-bit field (probe_type) in struct evsel.  The field
fits in existing padding after the bool fields, so struct size does not
grow.

The enum uses PROBE__UNKNOWN (0) as the uninitialized sentinel —
explicitly set in evsel__init() — so the lookup happens on first use.
PROBE__NOPE (1) caches "not a probe" to avoid repeated negative lookups.

PMU-based probes (kprobe/uprobe PMU) are detected by PMU name.
Ftrace-based dynamic probes (created via tracefs, reported as PMU
"tracepoint") are detected by the __probe_ip field that the kernel
adds to all dynamic probe formats.  This covers kprobes, uprobes, and
fprobes regardless of their group/system name.

Cc: Aaron Tomlin <atomlin@atomlin.com>
Assisted-by: Claude:claude-opus-4.6
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>