Renaming the CallableState variadic attribute argument to be CallableStates. No functional changes intended.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@207836 91177308-0d34-0410-b5e6-96231b3b80d8
Updated the attribute tablegen emitter for variadic arguments to emit a range accessor in addition to the iterators. Updated code using iterators to use range-based for loops.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@207837 91177308-0d34-0410-b5e6-96231b3b80d8