Remove SynchronizationScope::Other

Added in b761538, it started out already
unused.

Author: Mark-Simulacrum

src/librustc_codegen_llvm/llvm/ffi.rs

@@ -337,17 +337,13 @@ impl AtomicOrdering {
 #[derive(Copy, Clone)]
 #[repr(C)]
 pub enum SynchronizationScope {
-    // FIXME: figure out if this variant is needed at all.
-    #[allow(dead_code)]
-    Other,
     SingleThread,
     CrossThread,
 }
 
 impl SynchronizationScope {
     pub fn from_generic(sc: rustc_codegen_ssa::common::SynchronizationScope) -> Self {
         match sc {
-            rustc_codegen_ssa::common::SynchronizationScope::Other => SynchronizationScope::Other,
             rustc_codegen_ssa::common::SynchronizationScope::SingleThread => {
                 SynchronizationScope::SingleThread
             }

src/librustc_codegen_ssa/common.rs

@@ -72,9 +72,6 @@ pub enum AtomicOrdering {
 }
 
 pub enum SynchronizationScope {
-    // FIXME: figure out if this variant is needed at all.
-    #[allow(dead_code)]
-    Other,
     SingleThread,
     CrossThread,
 }

src/rustllvm/RustWrapper.cpp

@@ -366,7 +366,6 @@ LLVMRustBuildAtomicCmpXchg(LLVMBuilderRef B, LLVMValueRef Target,
 }
 
 enum class LLVMRustSynchronizationScope {
-  Other,
   SingleThread,
   CrossThread,
 };