Introduce PCHReader::GetTranslationUnitDecl() and use it instead of ReadDeclRecord when initializing.

ReadDeclRecord would hit assertion if the translation unit declaration was already loaded during
IdentifierInfo initialization.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@107885 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed