Adding a new code owners file for clang-tools-extra.

Populated file with known existing owners.

llvm-svn: 177083

clang-tools-extra/CODE_OWNERS.TXT

+This file is a list of the people responsible for ensuring that patches for a
+particular tool are reviewed, either by themself or by someone else. They are
+also the gatekeepers for their part of Clang, with the final word on what goes
+in or not.
+
+The list is sorted by surname and formatted to allow easy grepping and
+beautification by scripts.  The fields are: name (N), email (E), web-address
+(W), PGP key ID and fingerprint (P), description (D), and snail-mail address
+(S).
+
+N: Edwin Vane
+E: edwin.vane@intel.com
+D: cpp11-migrate