ASTUnit: Don't check that input files exist when parsing ASTs from the command
line -- they may be remapped (fake) files. This is useful for testing parsing
entirely from memory.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@94395 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed