rustc: remove linker_private/linker_private_weak

Remove the linker_private and linker_private_weak linkage attributes,
they have been superseded by private and private_weak and have been
removed in upstream LLVM in commit r203866.

Author: bnoordhuis

src/librustc/lib/llvm.rs

@@ -59,8 +59,6 @@ pub enum Linkage {
     ExternalWeakLinkage = 12,
     GhostLinkage = 13,
     CommonLinkage = 14,
-    LinkerPrivateLinkage = 15,
-    LinkerPrivateWeakLinkage = 16,
 }
 
 #[deriving(Clone)]

src/librustc/middle/trans/foreign.rs

@@ -121,8 +121,6 @@ pub fn llvm_linkage_by_name(name: &str) -> Option<Linkage> {
         "extern_weak" => Some(lib::llvm::ExternalWeakLinkage),
         "external" => Some(lib::llvm::ExternalLinkage),
         "internal" => Some(lib::llvm::InternalLinkage),
-        "linker_private" => Some(lib::llvm::LinkerPrivateLinkage),
-        "linker_private_weak" => Some(lib::llvm::LinkerPrivateWeakLinkage),
         "linkonce" => Some(lib::llvm::LinkOnceAnyLinkage),
         "linkonce_odr" => Some(lib::llvm::LinkOnceODRLinkage),
         "private" => Some(lib::llvm::PrivateLinkage),