Improve diagnostics for malformed constructor declarations (where lookup for
the type of the first parameter fails, and it is the only, unnamed, parameter).


git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@202759 91177308-0d34-0410-b5e6-96231b3b80d8
Objective-C. Fixes a regression when figuring out linkage
for metadata symbols for forward referenced protocols which 
are never defined.  // rdar://16203115


git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@202761 91177308-0d34-0410-b5e6-96231b3b80d8