Missing `alias` support in `mlir::LLVM::GlobalOp`

[bcardosolopes]

While working on ClangIR to LLVM lowering, we want to generate this kind of LLVM IR code:

@_ZN1BD1Ev = dso_local unnamed_addr alias void (ptr), ptr @_ZN1BD2Ev
@_ZN1CD2Ev = dso_local unnamed_addr alias void (ptr), ptr @_ZN1BD2Ev
@_ZN1CD1Ev = dso_local unnamed_addr alias void (ptr), ptr @_ZN1BD2Ev
 
define dso_local void @_ZN1BD2Ev(ptr noundef nonnull align 8 dereferenceable(9) %this) unnamed_addr #0 {

One of the reasons it's not possible it's because there's no support for alias (the other one will be filed in another issue)

[llvmbot]

@llvm/issue-subscribers-mlir-llvm

Author: Bruno Cardoso Lopes (bcardosolopes)

While working on ClangIR to LLVM lowering, we want to generate this kind of LLVM IR code:

@<!-- -->_ZN1BD1Ev = dso_local unnamed_addr alias void (ptr), ptr @<!-- -->_ZN1BD2Ev
@<!-- -->_ZN1CD2Ev = dso_local unnamed_addr alias void (ptr), ptr @<!-- -->_ZN1BD2Ev
@<!-- -->_ZN1CD1Ev = dso_local unnamed_addr alias void (ptr), ptr @<!-- -->_ZN1BD2Ev
 
define dso_local void @<!-- -->_ZN1BD2Ev(ptr noundef nonnull align 8 dereferenceable(9) %this) unnamed_addr #<!-- -->0 {

One of the reasons it's not possible it's because there's no support for alias (the other one will be filed in another issue)

[bcardosolopes]

More ClangIR specific details in: llvm/clangir#1065

[smeenai]

LLVM has a first-class notion of an alias, so we might want a dedicated op for this in the LLVM dialect as well.

[bcardosolopes]

LLVM has a first-class notion of an alias, so we might want a dedicated op for this in the LLVM dialect as well.

@smeenai that sounds reasonable.
Assigning this issue to me, should work on a solution for it soon