Adding const-qualifiers to auto declarations. NFC.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@215704 91177308-0d34-0410-b5e6-96231b3b80d8
There are no overloads of this virtual function, nor are there any callers of it. NFC.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@215705 91177308-0d34-0410-b5e6-96231b3b80d8
Const-correctness, return-after-else, and formatting updates. NFC.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@215706 91177308-0d34-0410-b5e6-96231b3b80d8