[preprocessing record] Add some sanity checks for the preprocessed entity index
to make sure we don't crash on release if the index is not valid.

rdar://13089714

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175010 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed