Renamed RefersToEnclosingLocal bitfield to RefersToCapturedVariable.
Bitfield RefersToEnclosingLocal of Stmt::DeclRefExprBitfields renamed to RefersToCapturedVariable to reflect latest changes introduced in commit 224323. Also renamed method Expr::refersToEnclosingLocal() to Expr::refersToCapturedVariable() and comments for constant arguments.
No functional changes.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@224329 91177308-0d34-0410-b5e6-96231b3b80d8