Add ImmtableString more property

Add name, addr space and not null added to the end of string
The name is required for the crossliner to include as global variable

include/llvm-dialects/Dialect/Dialect.td

@@ -11,7 +11,7 @@
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
- * limitations under the License. 
+ * limitations under the License.
  */
 
 def args;
@@ -69,7 +69,7 @@ class Attr<string cppType_> : MetaType {
   // A check statement that is issued before using the C++ value in builders.
   // $0 is the C++ value.
   string check = "";
-  
+
   // Overriding prevents generating a setter method. Attributes are mutable by default.
   bit isImmutable = false;
 }
@@ -280,11 +280,11 @@ def : AttrLlvmType<AttrI32, I32>;
 def : AttrLlvmType<AttrI64, I64>;
 
 def ImmutableStringAttr : Attr<"::llvm::StringRef"> {
-  let toLlvmValue = [{ $_builder.CreateGlobalString($0) }];
+  let toLlvmValue = [{ $_builder.CreateGlobalString($0, "str", 4) }];
   let fromLlvmValue = [{ ::llvm::cast<::llvm::ConstantDataArray>(::llvm::cast<::llvm::GlobalVariable>($0)->getInitializer())->getAsString() }];
   let isImmutable = true;
 }
- 
+
 // Global string variables are essentially pointers in addrspace(0).
 def : AttrLlvmType<ImmutableStringAttr, Ptr>;