Set storage class of julia globals to dllimport on windows to avoid auto-import weirdness

Co-authored-by: Cody Tapscott <84105208+topolarity@users.noreply.github.com>

Author: gbaraldi

src/codegen.cpp

@@ -493,9 +493,12 @@ struct JuliaVariable {
         if (GlobalValue *V = m->getNamedValue(name))
             return cast<GlobalVariable>(V);
         auto T_size = m->getDataLayout().getIntPtrType(m->getContext());
-        return new GlobalVariable(*m, _type(T_size),
+        auto var = new GlobalVariable(*m, _type(T_size),
                 isconst, GlobalVariable::ExternalLinkage,
                 NULL, name);
+        if (Triple(m->getTargetTriple()).isOSWindows())
+            var->setDLLStorageClass(GlobalValue::DLLStorageClassTypes::DLLImportStorageClass); // This is necessary to avoid auto import issues
+        return var;
     }
     GlobalVariable *realize(jl_codectx_t &ctx);
 };