Merge pull request #8886 from ethereum/pragma-once

Add header guard to two files

libyul/AsmJsonConverter.h

@@ -20,6 +20,8 @@
  * Converts inline assembly AST to JSON format
  */
 
+#pragma once
+
 #include <libyul/AsmDataForward.h>
 #include <liblangutil/SourceLocation.h>
 #include <json/json.h>

tools/solidityUpgrade/SourceTransform.h

@@ -15,6 +15,8 @@
 	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#pragma once
+
 #include <libsolidity/analysis/OverrideChecker.h>
 
 #include <libsolidity/ast/AST.h>