Move Storage and StorageAllocator out of the PartialDiagnostic class so we can forward declare them.

Let ASTContext allocate the storage in its BumpPtrAllocator.
This will help us remove ASTContext's depedency on PartialDiagnostic.h soon.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@149780 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed