MFC r254581:

Pull in r188716 from upstream clang trunk:

  PR16727: don't try to evaluate a potentially value-dependent
  expression when checking for missing parens in &&/|| expressions.

This fixes an assertion encountered when building the lang/sdcc port.

Reported by:	kwm
MFC r254582:

Pull in r182983 from upstream clang trunk:

  Fix handling of braced-init-list as reference initializer within
  aggregate initialization. Previously we would incorrectly require an
  extra set of braces around such initializers.

Pull in r188718 from upstream clang trunk:

  Handle init lists and _Atomic fields.

  Fixes PR16931.

These fixes are needed for the atomic_flag type to work correctly in our
stdatomic.h.

Requested by:	theraven