Sema::ActOnStartProtocolInterface(): Make sure the protocol decl has a valid start location.

The following case resulted in an invalid start location:

// start location not being set for ObjCProtocolDecl AST (when a forward reference is in scope).
@protocol Buggy;

@protocol Buggy 
@optional
- whatever;
@end



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@54740 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed