-Wunsequenced: if the LHS of an &&, || or ?: is not constant, check for
unsequenced operations in the RHS. We don't compare the RHS with the rest of
the expression yet; such checks will need care to avoid diagnosing unsequenced
operations which are both in conditionally-evaluated subexpressions which
actually can't occur together, such as in '(b && ++x) + (!b && ++x)'.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172760 91177308-0d34-0410-b5e6-96231b3b80d8
Parsing support for C11's _Noreturn keyword. No semantics yet.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172761 91177308-0d34-0410-b5e6-96231b3b80d8
Format strings: don't ever convert %+d to %lu.

Presumably, if the printf format has the sign explicitly requested, the user
wants to treat the data as signed.

This is a fix-up for r172739, and also includes several test changes that
didn't make it into that commit.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172762 91177308-0d34-0410-b5e6-96231b3b80d8