Checking in ActOnVariableDeclarator computes and caches the linkage using
the non-deduced auto type which defaults to external linkage. Depending on
how the auto type is deduced linkage can change and conflict with the
cached linkage, hitting asserts.
llvm-svn: 199774
This fixes pr14946. The problem was that the linkage computation was done too
early, so things like "extern int a;" would be given external linkage, even if
a previous declaration was static.
llvm-svn: 172667