Merge branch 'add-support-version-java18' into 'master'

add support of Java 18

See merge request !323

asm-util/src/main/java/org/objectweb/asm/util/ASMifier.java

@@ -107,6 +107,7 @@ public class ASMifier extends Printer {
     classVersions.put(Opcodes.V15, "V15");
     classVersions.put(Opcodes.V16, "V16");
     classVersions.put(Opcodes.V17, "V17");
+    classVersions.put(Opcodes.V18, "V18");
     CLASS_VERSIONS = Collections.unmodifiableMap(classVersions);
   }
 

asm/src/main/java/org/objectweb/asm/ClassReader.java

@@ -194,7 +194,7 @@ public class ClassReader {
     this.b = classFileBuffer;
     // Check the class' major_version. This field is after the magic and minor_version fields, which
     // use 4 and 2 bytes respectively.
-    if (checkClassVersion && readShort(classFileOffset + 6) > Opcodes.V17) {
+    if (checkClassVersion && readShort(classFileOffset + 6) > Opcodes.V18) {
       throw new IllegalArgumentException(
           "Unsupported class file major version " + readShort(classFileOffset + 6));
     }

asm/src/main/java/org/objectweb/asm/Opcodes.java

@@ -283,6 +283,7 @@ public interface Opcodes {
   int V15 = 0 << 16 | 59;
   int V16 = 0 << 16 | 60;
   int V17 = 0 << 16 | 61;
+  int V18 = 0 << 16 | 62;
 
   /**
    * Version flag indicating that the class is using 'preview' features.

asm/src/test/java/org/objectweb/asm/ConstantsTest.java

@@ -250,6 +250,7 @@ public class ConstantsTest {
       case "V15":
       case "V16":
       case "V17":
+      case "V18":
         return ConstantType.CLASS_VERSION;
       case "ACC_PUBLIC":
       case "ACC_PRIVATE":