perf scripts python: exported-sql-viewer.py: Add IPC information to the Branch reports

perf scripts python: exported-sql-viewer.py: Add IPC information to the Branch reports

Enhance the "All branches" and "Selected branches" reports to display IPC
information if it is available.

Committer testing:

So, testing this I noticed that it all starts with the left arrow in every
line, that should mean there is some tree there, i.e. look at all those ▶
symbols:

Reports -> All Branches:

Time              CPU Command         PID   TID   Branch Type  In Tx  Insn Cnt  Cyc Cnt  IPC  Branch
▶ 187836112195670 7   simple-retpolin 23003 23003 trace begin  No     0         0        0               0 unknown (unknown) -> 7f6f33d4f110
+_start (ld-2.28.so)
▶ 187836112195987 7   simple-retpolin 23003 23003 trace end    No     0         883      0    7f6f33d4f110 _start (ld-2.28.so) -> 0 unknown
+(unknown)
▶ 187836112199189 7   simple-retpolin 23003 23003 trace begin  No     0         0        0               0 unknown (unknown) -> 7f6f33d4f110
+_start (ld-2.28.so)
▶ 187836112199189 7   simple-retpolin 23003 23003 call         No     0         0        0    7f6f33d4f113 _start+0x3 (ld-2.28.so) -> 7f6f33d4ff50
+_dl_start (ld-2.28.so)
▶ 187836112199544 7   simple-retpolin 23003 23003 trace end    No     17        996      0.02 7f6f33d4ff73 _dl_start+0x23 (ld-2.28.so) -> 0
+unknown (unknown)
▶ 187836112200939 7   simple-retpolin 23003 23003 trace begin  No     0         0        0               0 unknown (unknown) -> 7f6f33d4ff73
+_dl_start+0x23 (ld-2.28.so)
▶ 187836112201229 7   simple-retpolin 23003 23003 trace end    No     1         816      0.00 7f6f33d4ff7a _dl_start+0x2a (ld-2.28.so) -> 0
+unknown (unknown)
▶ 187836112203500 7   simple-retpolin 23003 23003 trace begin  No     0         0        0               0 unknown (unknown) -> 7f6f33d4ff7a
+_dl_start+0x2a (ld-2.28.so)

But if you click on it, that ▶ disappears and a new click doesn't make
it reappear, looks buggy, minor oddity, reported to Adrian.

Reports -> Selected Branches, then ask for branches in the ld-2.28.so
DSO:

Time               CPU  Command          PID    TID    Branch Type        In Tx  Insn Cnt  Cyc Cnt  IPC   Branch
▶ 187836112195987  7    simple-retpolin  23003  23003  trace end          No     0         883      0     7f6f33d4f110 _start (ld-2.28.so) -> 0 unknown (unknown)
▶ 187836112199189  7    simple-retpolin  23003  23003  trace begin        No     0         0        0                0 unknown (unknown) -> 7f6f33d4f110 _start (ld-2.28.so)
▶ 187836112199189  7    simple-retpolin  23003  23003  call               No     0         0        0     7f6f33d4f113 _start+0x3 (ld-2.28.so) -> 7f6f33d4ff50 _dl_start (ld-2.28.so)
▶ 187836112199544  7    simple-retpolin  23003  23003  trace end          No     17        996      0.02  7f6f33d4ff73 _dl_start+0x23 (ld-2.28.so) -> 0 unknown (unknown)
▶ 187836112200939  7    simple-retpolin  23003  23003  trace begin        No     0         0        0                0 unknown (unknown) -> 7f6f33d4ff73 _dl_start+0x23 (ld-2.28.so)
▶ 187836112201229  7    simple-retpolin  23003  23003  trace end          No     1         816      0.00  7f6f33d4ff7a _dl_start+0x2a (ld-2.28.so) -> 0 unknown (unknown)
▶ 187836112203500  7    simple-retpolin  23003  23003  trace begin        No     0         0        0                0 unknown (unknown) -> 7f6f33d4ff7a _dl_start+0x2a (ld-2.28.so)
▶ 187836112203528  7    simple-retpolin  23003  23003  unconditional jump No     0         0        0     7f6f33d4ffe7 _dl_start+0x97 (ld-2.28.so) -> 7f6f33d5000b _dl_start+0xbb (ld-2.28.so)
▶ 187836112203528  7    simple-retpolin  23003  23003  conditional jump   No     0         0        0     7f6f33d5000f _dl_start+0xbf (ld-2.28.so) -> 7f6f33d4fffb _dl_start+0xab (ld-2.28.so)
▶ 187836112203528  7    simple-retpolin  23003  23003  conditional jump   No     0         0        0     7f6f33d5000f _dl_start+0xbf (ld-2.28.so) -> 7f6f33d4fffb _dl_start+0xab (ld-2.28.so)
▶ 187836112203539  7    simple-retpolin  23003  23003  conditional jump   No     0         0        0     7f6f33d50025 _dl_start+0xd5 (ld-2.28.so) -> 7f6f33d50210 _dl_start+0x2c0 (ld-2.28.so)
▶ 187836112203539  7    simple-retpolin  23003  23003  conditional jump   No     0         0        0     7f6f33d5021a _dl_start+0x2ca (ld-2.28.so) -> 7f6f33d50360 _dl_start+0x410 (ld-2.28.so)
▶ 187836112203539  7    simple-retpolin  23003  23003  unconditional jump No     0         0        0     7f6f33d50377 _dl_start+0x427 (ld-2.28.so) -> 7f6f33d4ffff _dl_start+0xaf (ld-2.28.so)
▶ 187836112203539  7    simple-retpolin  23003  23003  conditional jump   No     0         0        0     7f6f33d5000f _dl_start+0xbf (ld-2.28.so) -> 7f6f33d4fffb _dl_start+0xab (ld-2.28.so)
▶ 187836112203562  7    simple-retpolin  23003  23003  conditional jump   No     0         0        0     7f6f33d5000f _dl_start+0xbf (ld-2.28.so) -> 7f6f33d4fffb _dl_start+0xab (ld-2.28.so)

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190520113728.14389-19-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>