MFC Clang debug info crash fix

r271282: Merge Clang debug info crash fix rev 200797:

      Debug info: fix a crasher when when emitting debug info for
      not-yet-completed templated types. getTypeSize() needs a complete type.

      rdar://problem/15931354

r271283: Add clang patch for r271282

  Note that r271282 contains only the src change from Clang rev 200797.
  This patch file includes two follow-on changes to the test case, which
  do not apply to the copy in the FreeBSD tree.

  Upstream Clang revisions:

  200797:

      Debug info: fix a crasher when when emitting debug info for
      not-yet-completed templated types. getTypeSize() needs a complete type.

      rdar://problem/15931354

  200798:

      Simplify testcase from r200797 some more.

  200805:

      Further simplify r200797 and add an explanatory comment.

PR:		193347
Approved by:	re
Sponsored by:	DARPA, AFRL