ClassReader relies on autoboxing for reuse of cached primitive values

Issue: SPR-12365

spring-core/src/main/java/org/springframework/asm/ClassReader.java

@@ -1830,24 +1830,19 @@ public class ClassReader {
             v += 2;
             break;
         case 'B': // pointer to CONSTANT_Byte
-            av.visit(name,
-                    new Byte((byte) readInt(items[readUnsignedShort(v)])));
+            av.visit(name, (byte) readInt(items[readUnsignedShort(v)]));
             v += 2;
             break;
         case 'Z': // pointer to CONSTANT_Boolean
-            av.visit(name,
-                    readInt(items[readUnsignedShort(v)]) == 0 ? Boolean.FALSE
-                            : Boolean.TRUE);
+            av.visit(name, readInt(items[readUnsignedShort(v)]) == 0 ? Boolean.FALSE : Boolean.TRUE);
             v += 2;
             break;
         case 'S': // pointer to CONSTANT_Short
-            av.visit(name, new Short(
-                    (short) readInt(items[readUnsignedShort(v)])));
+            av.visit(name, (short) readInt(items[readUnsignedShort(v)]));
             v += 2;
             break;
         case 'C': // pointer to CONSTANT_Char
-            av.visit(name, new Character(
-                    (char) readInt(items[readUnsignedShort(v)])));
+            av.visit(name, (char) readInt(items[readUnsignedShort(v)]));
             v += 2;
             break;
         case 's': // pointer to CONSTANT_Utf8
@@ -2471,13 +2466,13 @@ public class ClassReader {
         int index = items[item];
         switch (b[index - 1]) {
         case ClassWriter.INT:
-            return new Integer(readInt(index));
+            return readInt(index);
         case ClassWriter.FLOAT:
-            return new Float(Float.intBitsToFloat(readInt(index)));
+            return Float.intBitsToFloat(readInt(index));
         case ClassWriter.LONG:
-            return new Long(readLong(index));
+            return readLong(index);
         case ClassWriter.DOUBLE:
-            return new Double(Double.longBitsToDouble(readLong(index)));
+            return Double.longBitsToDouble(readLong(index));
         case ClassWriter.CLASS:
             return Type.getObjectType(readUTF8(index, buf));
         case ClassWriter.STR: