Rework USR generation for symbols with no linkage.  Many of the USRs are now shortened,
and we now include the file name that declares the symbol with no linkage in the USR.
USRs for such symbols are generated only in restructed cases, e.g., anonymous enum declarations,
typedefs, etc.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@101542 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed