[SandboxIR] Warnings on Windows when building LLVM with clang-cl.exe

[farzonl]

1 warning generated.
[2861/4875] Building CXX object lib/SandboxIR/CMakeFiles/LLVMSandboxIR.dir/Constant.cpp.obj
D:/projects/llvm-project/llvm/lib/SandboxIR/Constant.cpp(309,52): warning: duplicate explicit instantiation of 'operator()' ignored as a Microsoft extension [-Wmicrosoft-template]
  309 |                   llvm::GlobalObject>::LLVMGVToGV::operator()(llvm::GlobalIFunc
      |                                                    ^
D:/projects/llvm-project/llvm/include\llvm/SandboxIR/Constant.h(804,52): note: previous explicit instantiation is here
  804 |                   llvm::GlobalObject>::LLVMGVToGV::operator()(llvm::GlobalIFunc
      |                                                    ^
D:/projects/llvm-project/llvm/lib/SandboxIR/Constant.cpp(314,17): warning: duplicate explicit instantiation of 'operator()' ignored as a Microsoft extension [-Wmicrosoft-template]
  314 |     LLVMGVToGV::operator()(llvm::Function &LLVMGV) const;
      |                 ^
D:/projects/llvm-project/llvm/include\llvm/SandboxIR/Constant.h(809,17): note: previous explicit instantiation is here
  809 |     LLVMGVToGV::operator()(llvm::Function &LLVMGV) const;
      |                 ^
D:/projects/llvm-project/llvm/lib/SandboxIR/Constant.cpp(318,38): warning: duplicate explicit instantiation of 'operator()' ignored as a Microsoft extension [-Wmicrosoft-template]
  318 |     llvm::GlobalObject>::LLVMGVToGV::operator()(llvm::GlobalVariable &LLVMGV)
      |                                      ^
D:/projects/llvm-project/llvm/include\llvm/SandboxIR/Constant.h(813,38): note: previous explicit instantiation is here
  813 |     llvm::GlobalObject>::LLVMGVToGV::operator()(llvm::GlobalVariable &LLVMGV)
      |                                      ^
D:/projects/llvm-project/llvm/lib/SandboxIR/Constant.cpp(322,51): warning: duplicate explicit instantiation of 'operator()' ignored as a Microsoft extension [-Wmicrosoft-template]
  322 |                   llvm::GlobalValue>::LLVMGVToGV::operator()(llvm::GlobalAlias
      |                                                   ^
D:/projects/llvm-project/llvm/include\llvm/SandboxIR/Constant.h(817,51): note: previous explicit instantiation is here
D:/projects/llvm-project/llvm/include\llvm/SandboxIR/Constant.h(813,38): note: previous explicit instantiation is here
  813 |     llvm::GlobalObject>::LLVMGVToGV::operator()(llvm::GlobalVariable &LLVMGV)
      |                                      ^
D:/projects/llvm-project/llvm/lib/SandboxIR/Constant.cpp(322,51): warning: duplicate explicit instantiation of 'operator()' ignored as a Microsoft extension [-Wmicrosoft-template]
  322 |                   llvm::GlobalValue>::LLVMGVToGV::operator()(llvm::GlobalAlias
      |                                                   ^
D:/projects/llvm-project/llvm/include\llvm/SandboxIR/Constant.h(813,38): note: previous explicit instantiation is here
  813 |     llvm::GlobalObject>::LLVMGVToGV::operator()(llvm::GlobalVariable &LLVMGV)
      |                                      ^
D:/projects/llvm-project/llvm/lib/SandboxIR/Constant.cpp(322,51): warning: duplicate explicit instantiation of 'operator()' ignored as a Microsoft extension [-Wmicrosoft-template]
  322 |                   llvm::GlobalValue>::LLVMGVToGV::operator()(llvm::GlobalAlias
D:/projects/llvm-project/llvm/include\llvm/SandboxIR/Constant.h(813,38): note: previous explicit instantiation is here
  813 |     llvm::GlobalObject>::LLVMGVToGV::operator()(llvm::GlobalVariable &LLVMGV)
      |                                      ^
D:/projects/llvm-project/llvm/lib/SandboxIR/Constant.cpp(322,51): warning: duplicate explicit instantiation of 'operator()' ignored as a Microsoft extension [-Wmicrosoft-template]
D:/projects/llvm-project/llvm/include\llvm/SandboxIR/Constant.h(813,38): note: previous explicit instantiation is here
  813 |     llvm::GlobalObject>::LLVMGVToGV::operator()(llvm::GlobalVariable &LLVMGV)
      |                                      ^
D:/projects/llvm-project/llvm/include\llvm/SandboxIR/Constant.h(813,38): note: previous explicit instantiation is here
  813 |     llvm::GlobalObject>::LLVMGVToGV::operator()(llvm::GlobalVariable &LLVMGV)
      |                                      ^
D:/projects/llvm-project/llvm/include\llvm/SandboxIR/Constant.h(813,38): note: previous explicit instantiation is here
  813 |     llvm::GlobalObject>::LLVMGVToGV::operator()(llvm::GlobalVariable &LLVMGV)
D:/projects/llvm-project/llvm/include\llvm/SandboxIR/Constant.h(813,38): note: previous explicit instantiation is here
  813 |     llvm::GlobalObject>::LLVMGVToGV::operator()(llvm::GlobalVariable &LLVMGV)
D:/projects/llvm-project/llvm/include\llvm/SandboxIR/Constant.h(813,38): note: previous explicit instantiation is here
D:/projects/llvm-project/llvm/include\llvm/SandboxIR/Constant.h(813,38): note: previous explicit instantiation is here
D:/projects/llvm-project/llvm/include\llvm/SandboxIR/Constant.h(813,38): note: previous explicit instantiation is here
D:/projects/llvm-project/llvm/include\llvm/SandboxIR/Constant.h(813,38): note: previous explicit instantiation is here
  813 |     llvm::GlobalObject>::LLVMGVToGV::operator()(llvm::GlobalVariable &LLVMGV)
      |                                      ^
D:/projects/llvm-project/llvm/lib/SandboxIR/Constant.cpp(322,51): warning: duplicate explicit instantiation of 'operator()' ignored as a Microsoft extension [-Wmicrosoft-template]
  322 |                   llvm::GlobalValue>::LLVMGVToGV::operator()(llvm::GlobalAlias
      |                                                   ^
D:/projects/llvm-project/llvm/include\llvm/SandboxIR/Constant.h(817,51): note: previous explicit instantiation is here
  817 |                   llvm::GlobalValue>::LLVMGVToGV::operator()(llvm::GlobalAlias
      |                                                   ^

[bogner]

@fsfod Are we planning on doing anything about this? These warnings still persist almost six months later, and in both conversations about resolving them (#111940 (comment), #116387 (review)) you suggested some change or other but AFAICT never followed up. I don't know enough about the SandboxIR library to be confident in fixing this myself.