Improve ClassLiteralTransformer

The unsigned client has a Class.forName() method with two differences:

* The NoClassDefFoundError is created with a slightly different sequence
  of instructions.

* The arms of the if/else statement for initializing the synthetic field
  if it is null are swapped.

This commit adds support for translating Class.forName() methods with
either or both of these differences to the modern LDC form.

Signed-off-by: Graham <gpe@openrs2.dev>

deob/src/main/java/dev/openrs2/deob/transform/ClassLiteralTransformer.kt

@@ -58,9 +58,18 @@ class ClassLiteralTransformer : Transformer() {
     override fun transformCode(classPath: ClassPath, library: Library, clazz: ClassNode, method: MethodNode): Boolean {
         for (match in CLASS_LITERAL_MATCHER.match(method)) {
             val getstatic1 = MemberRef(match[0] as FieldInsnNode)
-            val putstatic = MemberRef(match[5] as FieldInsnNode)
-            val getstatic2 = MemberRef(match[7] as FieldInsnNode)
-            val invokestatic = MemberRef(match[3] as MethodInsnNode)
+            val putstatic: MemberRef
+            val getstatic2: MemberRef
+            val invokestatic: MemberRef
+            if (match[1].opcode == Opcodes.IFNONNULL) {
+                putstatic = MemberRef(match[5] as FieldInsnNode)
+                getstatic2 = MemberRef(match[7] as FieldInsnNode)
+                invokestatic = MemberRef(match[3] as MethodInsnNode)
+            } else {
+                putstatic = MemberRef(match[7] as FieldInsnNode)
+                getstatic2 = MemberRef(match[2] as FieldInsnNode)
+                invokestatic = MemberRef(match[5] as MethodInsnNode)
+            }
 
             if (getstatic1 != putstatic || putstatic != getstatic2) {
                 continue
@@ -78,10 +87,9 @@ class ClassLiteralTransformer : Transformer() {
                 continue
             }
 
-            for ((i, insn) in match.withIndex()) {
-                if (i == 2) {
-                    val ldc = insn as LdcInsnNode
-                    ldc.cst = Type.getObjectType((ldc.cst as String).toInternalClassName())
+            for (insn in match) {
+                if (insn is LdcInsnNode) {
+                    insn.cst = Type.getObjectType((insn.cst as String).toInternalClassName())
                 } else {
                     method.instructions.remove(insn)
                 }
@@ -103,10 +111,15 @@ class ClassLiteralTransformer : Transformer() {
     companion object {
         private val logger = InlineLogger()
         private val CLASS_FOR_NAME_MATCHER = InsnMatcher.compile(
-            "^ALOAD INVOKESTATIC ARETURN ASTORE NEW DUP INVOKESPECIAL ALOAD INVOKEVIRTUAL ATHROW$"
+            """
+            ^ALOAD INVOKESTATIC ARETURN
+            ASTORE NEW DUP (ALOAD INVOKEVIRTUAL INVOKESPECIAL | INVOKESPECIAL ALOAD INVOKEVIRTUAL) ATHROW$
+        """
         )
+
+        private const val NULL_ARM = "LDC INVOKESTATIC DUP PUTSTATIC"
         private val CLASS_LITERAL_MATCHER = InsnMatcher.compile(
-            "GETSTATIC IFNONNULL LDC INVOKESTATIC DUP PUTSTATIC GOTO GETSTATIC"
+            "GETSTATIC (IFNONNULL $NULL_ARM GOTO GETSTATIC | IFNULL GETSTATIC GOTO $NULL_ARM)"
         )
     }
 }