[C++11] Convert sort predicates into lambdas.

No functionality change.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@203289 91177308-0d34-0410-b5e6-96231b3b80d8
[C++11] Revert uses of lambdas with array_pod_sort.

Looks like GCC implements the lambda->function pointer conversion differently.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@203293 91177308-0d34-0410-b5e6-96231b3b80d8