Move ASTUnit's handling of temporary files and the preamble file into a lazily-created static DenseMap.  This DenseMap is cleared (and the files erased) via an atexit routine in the case an ASTUnit is not destroyed.  Fixes <rdar://problem/10293367>.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@143115 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed