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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76385 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index 55ec9e5..d7acd14 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -281,19 +281,20 @@
   switch (GV->getLinkage()) {
   default: llvm_unreachable("Invalid linkage!");
   case GlobalValue::GhostLinkage:  // Map ghost linkage onto external.
-  case GlobalValue::ExternalLinkage:     return 0;
-  case GlobalValue::WeakAnyLinkage:      return 1;
-  case GlobalValue::AppendingLinkage:    return 2;
-  case GlobalValue::InternalLinkage:     return 3;
-  case GlobalValue::LinkOnceAnyLinkage:  return 4;
-  case GlobalValue::DLLImportLinkage:    return 5;
-  case GlobalValue::DLLExportLinkage:    return 6;
-  case GlobalValue::ExternalWeakLinkage: return 7;
-  case GlobalValue::CommonLinkage:       return 8;
-  case GlobalValue::PrivateLinkage:      return 9;
-  case GlobalValue::WeakODRLinkage:      return 10;
-  case GlobalValue::LinkOnceODRLinkage:  return 11;
-  case GlobalValue::AvailableExternallyLinkage:  return 12;
+  case GlobalValue::ExternalLinkage:            return 0;
+  case GlobalValue::WeakAnyLinkage:             return 1;
+  case GlobalValue::AppendingLinkage:           return 2;
+  case GlobalValue::InternalLinkage:            return 3;
+  case GlobalValue::LinkOnceAnyLinkage:         return 4;
+  case GlobalValue::DLLImportLinkage:           return 5;
+  case GlobalValue::DLLExportLinkage:           return 6;
+  case GlobalValue::ExternalWeakLinkage:        return 7;
+  case GlobalValue::CommonLinkage:              return 8;
+  case GlobalValue::PrivateLinkage:             return 9;
+  case GlobalValue::WeakODRLinkage:             return 10;
+  case GlobalValue::LinkOnceODRLinkage:         return 11;
+  case GlobalValue::AvailableExternallyLinkage: return 12;
+  case GlobalValue::LinkerPrivateLinkage:       return 13;
   }
 }