[ExecutionEngine] Remove unused function cloneGlobalAliasDecl

[kazu]

Summary

The last use was removed by:

commit 6154c4115cd4b78d0171892aac21e340e72e32bd
Author: Lang Hames <[e-mail]>
Date:   Mon Sep 7 21:21:28 2020 -0700

[lhames]

Let's leave this one as-is for now for symmetry with the other utilities. We're in the process of rethinking the whole IndirectionUtils API and can revisit this then.

llvm/include/llvm/ExecutionEngine/Orc/IndirectionUtils.h

 /// between functions all refer to the versions in the new module.
 Function *cloneFunctionDecl(Module &Dst, const Function &F,
                             ValueToValueMapTy *VMap = nullptr);
 
 /// Clone a global variable declaration into a new module.
 GlobalVariable *cloneGlobalVariableDecl(Module &Dst, const GlobalVariable &GV,
                                         ValueToValueMapTy *VMap = nullptr);
 
-/// Clone a global alias declaration into a new module.
-GlobalAlias *cloneGlobalAliasDecl(Module &Dst, const GlobalAlias &OrigA,
-                                  ValueToValueMapTy &VMap);
-
 /// Introduce relocations to \p Sym in its own definition if there are any
 /// pointers formed via PC-relative address that do not already have a
 /// relocation.
 ///
 /// This is useful when introducing indirection via a stub function at link time
 /// without compiler support. If a function pointer is formed without a
 /// relocation, e.g. in the definition of \c foo
 ///

llvm/lib/ExecutionEngine/Orc/IndirectionUtils.cpp

GlobalVariable *NewGV = new GlobalVariable(
       GV.getLinkage(), nullptr, GV.getName(), nullptr,
       GV.getThreadLocalMode(), GV.getType()->getAddressSpace());
   NewGV->copyAttributesFrom(&GV);
   if (VMap)
     (*VMap)[&GV] = NewGV;
   return NewGV;
 }
 
-GlobalAlias* cloneGlobalAliasDecl(Module &Dst, const GlobalAlias &OrigA,
-                                  ValueToValueMapTy &VMap) {
-  assert(OrigA.getAliasee() && "Original alias doesn't have an aliasee?");
-  auto *NewA = GlobalAlias::create(OrigA.getValueType(),
-                                   OrigA.getType()->getPointerAddressSpace(),
-                                   OrigA.getLinkage(), OrigA.getName(), &Dst);
-  NewA->copyAttributesFrom(&OrigA);
-  VMap[&OrigA] = NewA;
-  return NewA;
-}
-
 Error addFunctionPointerRelocationsToCurrentSymbol(jitlink::Symbol &Sym,
                                                    jitlink::LinkGraph &G,
                                                    MCDisassembler &Disassembler,
                                                    MCInstrAnalysis &MIA) {
   // AArch64 appears to already come with the necessary relocations. Among other
   // architectures, only x86_64 is currently implemented here.
   if (G.getTargetTriple().getArch() != Triple::x86_64)
     return Error::success();