Silence a warning saying "typedef requires a name" from clang.

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@214247 91177308-0d34-0410-b5e6-96231b3b80d8
Use __linux__ macro throughout, instead of ocasional __linux.

__linux is not universally defined across all standards versions, compilers and architectures. Specifically at C99 and up, it's not defined in GCC on powerpc platform.

See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=28314

Bugzilla: http://llvm.org/bugs/show_bug.cgi?id=20380

Patch by Dimitri John Ledkov <dimitri.ledkov@canonical.com>



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@214291 91177308-0d34-0410-b5e6-96231b3b80d8
Merge upstream llvm.org r214291 into dev-llgs-local
Improved logging for lldb-launched exe for debugging.

* launch sync pipe log lines normalized.
* now display when child thread execs after sync, along
  with args and env content.
* now log on the success side of all the launch sync pipe operations.

Verified the sync pipe is working.  Now I need to address
llgs not handling the signaling around execs right (or something
similar).

Completes implementation of https://github.com/tfiala/lldb/issues/45.