Douglas Gregor 596b7cbc19 Implement a trivial, obvious optimization for deserialization of
redeclaration chains: only ever have the reader search for
redeclarations of the first (canonical) declaration, since we only
ever record redeclaration ranges for the that declaration. Searching
for redeclarations of non-canonical declarations will never find
anything, so it's a complete waste of time.

llvm-svn: 147055
2011-12-21 15:12:03 +00:00
..