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

include/llvm-c/Core.h

@@ -141,6 +141,7 @@ typedef enum {
   LLVMInternalLinkage,    /**< Rename collisions when linking (static
                                functions) */
   LLVMPrivateLinkage,     /**< Like Internal, but omit from symbol table */
+  LLVMLinkerPrivateLinkage, /**< Like Private, but linker removes. */
   LLVMDLLImportLinkage,   /**< Function to be imported from DLL */
   LLVMDLLExportLinkage,   /**< Function to be accessible from DLL */
   LLVMExternalWeakLinkage,/**< ExternalWeak linkage description */