perf callchain: Make brtype_stat in callchain_list optional

struct callchain_list is 352bytes in size, 232 of which are
brtype_stat. brtype_stat is only used for certain callchain_list
items so make it optional, allocating when necessary. So that
printing doesn't need to deal with an optional brtype_stat, pass
an empty/zero version.

Before:
```
struct callchain_list {
        u64                        ip;                   /*     0     8 */
        struct map_symbol          ms;                   /*     8    24 */
        struct {
                _Bool              unfolded;             /*    32     1 */
                _Bool              has_children;         /*    33     1 */
        };                                               /*    32     2 */

        /* XXX 6 bytes hole, try to pack */

        u64                        branch_count;         /*    40     8 */
        u64                        from_count;           /*    48     8 */
        u64                        predicted_count;      /*    56     8 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        u64                        abort_count;          /*    64     8 */
        u64                        cycles_count;         /*    72     8 */
        u64                        iter_count;           /*    80     8 */
        u64                        iter_cycles;          /*    88     8 */
        struct branch_type_stat    brtype_stat;          /*    96   232 */
        /* --- cacheline 5 boundary (320 bytes) was 8 bytes ago --- */
        const char  *              srcline;              /*   328     8 */
        struct list_head           list;                 /*   336    16 */

        /* size: 352, cachelines: 6, members: 13 */
        /* sum members: 346, holes: 1, sum holes: 6 */
        /* last cacheline: 32 bytes */
};
```

After:
```
struct callchain_list {
        u64                        ip;                   /*     0     8 */
        struct map_symbol          ms;                   /*     8    24 */
        struct {
                _Bool              unfolded;             /*    32     1 */
                _Bool              has_children;         /*    33     1 */
        };                                               /*    32     2 */

        /* XXX 6 bytes hole, try to pack */

        u64                        branch_count;         /*    40     8 */
        u64                        from_count;           /*    48     8 */
        u64                        predicted_count;      /*    56     8 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        u64                        abort_count;          /*    64     8 */
        u64                        cycles_count;         /*    72     8 */
        u64                        iter_count;           /*    80     8 */
        u64                        iter_cycles;          /*    88     8 */
        struct branch_type_stat *  brtype_stat;          /*    96     8 */
        const char  *              srcline;              /*   104     8 */
        struct list_head           list;                 /*   112    16 */

        /* size: 128, cachelines: 2, members: 13 */
        /* sum members: 122, holes: 1, sum holes: 6 */
};
```

Signed-off-by: Ian Rogers <[email protected]>
Cc: K Prateek Nayak <[email protected]>
Cc: Ravi Bangoria <[email protected]>
Cc: Sandipan Das <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: German Gomez <[email protected]>
Cc: James Clark <[email protected]>
Cc: Nick Terrell <[email protected]>
Cc: Sean Christopherson <[email protected]>
Cc: Changbin Du <[email protected]>
Cc: liuwenyu <[email protected]>
Cc: Yang Jihong <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Miguel Ojeda <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Leo Yan <[email protected]>
Cc: Kajol Jain <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Athira Rajeev <[email protected]>
Cc: Yanteng Si <[email protected]>
Cc: Liam Howlett <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>

0 files changed, 0 insertions, 0 deletions