Add plumbing for the `linker_private' linkage type. This type is meant for
"private" symbols which the assember shouldn't strip, but which the linker may
remove after evaluation. This is mostly useful for Objective-C metadata.

This is plumbing, so we don't have a use of it yet. More to come, etc.

llvm-svn: 76385
diff --git a/llvm/lib/Target/ELFTargetAsmInfo.cpp b/llvm/lib/Target/ELFTargetAsmInfo.cpp
index 752f475..0338ba4 100644
--- a/llvm/lib/Target/ELFTargetAsmInfo.cpp
+++ b/llvm/lib/Target/ELFTargetAsmInfo.cpp
@@ -77,6 +77,7 @@
     switch (F->getLinkage()) {
      default: llvm_unreachable("Unknown linkage type!");
      case Function::PrivateLinkage:
+     case Function::LinkerPrivateLinkage:
      case Function::InternalLinkage:
      case Function::DLLExportLinkage:
      case Function::ExternalLinkage: