Sema::ActOnStartProtocolInterface(): Make sure the protocol decl has a valid start location.
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: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@54740 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang