[PATCH v3 0/6] tr2: plug memory leaks + logic errors + Win32 & Linux feature parity

A hopefully final re-roll with minor commit message changes. Thanks everyone for the reviews!

Ævar Arnfjörð Bjarmason (6):
  tr2: remove NEEDSWORK comment for "non-procfs" implementations
  tr2: clarify TRACE2_PROCESS_INFO_EXIT comment under Linux
  tr2: stop leaking "thread_name" memory
  tr2: leave the parent list empty upon failure & don't leak memory
  tr2: do compiler enum check in trace2_collect_process_info()
  tr2: log N parent process names on Linux

 compat/linux/procinfo.c | 169 ++++++++++++++++++++++++++++++++++------
 trace2/tr2_tls.c        |   1 +
 2 files changed, 146 insertions(+), 24 deletions(-)

Range-diff against v2:
1:  8c649ce3b4 = 1:  306f14a0f7 tr2: remove NEEDSWORK comment for "non-procfs" implementations
2:  0150e3402a = 2:  a999e016a9 tr2: clarify TRACE2_PROCESS_INFO_EXIT comment under Linux
3:  1d835d6767 = 3:  45769da953 tr2: stop leaking "thread_name" memory
4:  1aa0dbc394 ! 4:  946140691f tr2: fix memory leak & logic error in 2f732bf15e6
    @@ Metadata
     Author: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
     
      ## Commit message ##
    -    tr2: fix memory leak & logic error in 2f732bf15e6
    +    tr2: leave the parent list empty upon failure & don't leak memory
     
         In a subsequent commit I'll be replacing most of this code to log N
         parents, but let's first fix bugs introduced in the recent
    @@ Commit message
         system where we could read the file from procfs.
     
         Let's move all the freeing of the memory to the end of the
    -    function. If we're still at STRBUF_INIT with "name" due to not haven
    +    function. If we're still at STRBUF_INIT with "name" due to not having
         taken the branch where the strbuf_read_file() succeeds freeing it is
    -    redundant, so we could move it into the body of the "if", but just
    +    redundant. So we could move it into the body of the "if", but just
         handling freeing the same way for all branches of the function makes
         it more readable.
     
5:  70fef093d8 = 5:  0bea5aa9c9 tr2: do compiler enum check in trace2_collect_process_info()
6:  f6aac90248 = 6:  6eac9986c3 tr2: log N parent process names on Linux