codegen: check addresspace before doing a bitcast for small tags (#51517)

Fixes JuliaGPU/GPUCompiler.jl#504. Similar to
#38424

Author: gbaraldi

src/cgutils.cpp

@@ -411,7 +411,13 @@ static Constant *literal_pointer_val_slot(jl_codectx_t &ctx, jl_value_t *p)
             // some common builtin datatypes have a special pool for accessing them by smalltag id
             Constant *tag = ConstantInt::get(getInt32Ty(ctx.builder.getContext()), addr->smalltag << 4);
             Constant *smallp = ConstantExpr::getInBoundsGetElementPtr(getInt8Ty(ctx.builder.getContext()), prepare_global_in(jl_Module, jl_small_typeof_var), tag);
-            return ConstantExpr::getBitCast(smallp, ctx.types().T_ppjlvalue);
+            auto ty = ctx.types().T_ppjlvalue;
+            if (ty->getPointerAddressSpace() == smallp->getType()->getPointerAddressSpace())
+                return ConstantExpr::getBitCast(smallp, ty);
+            else {
+                Constant *newsmallp = ConstantExpr::getAddrSpaceCast(smallp, ty);
+                return ConstantExpr::getBitCast(newsmallp, ty);
+            }
         }
         // DataTypes are prefixed with a +
         return julia_pgv(ctx, "+", addr->name->name, addr->name->module, p);