docs: added a comment about removed SCRIPT_ENABLE_DIP0020_OPCODES

Author: knst

src/script/interpreter.h

@@ -95,6 +95,12 @@ enum : uint32_t {
     //
     SCRIPT_VERIFY_NULLFAIL = (1U << 14),
 
+    // DIP0020_OPCODES - ignored.
+    // Was used to enable the opcodes listed in DIP0020
+    // (OP_CAT, OP_AND, OP_OR, OP_XOR, OP_DIV, OP_MOD, OP_SPLIT, OP_BIN2NUM,
+    // OP_NUM2BIN, OP_CHECKDATASIG, OP_CHECKDATASIGVERIFY).
+    // SCRIPT_ENABLE_DIP0020_OPCODES = (1U << 15),
+
     // Making OP_CODESEPARATOR and FindAndDelete fail
     //
     SCRIPT_VERIFY_CONST_SCRIPTCODE = (1U << 16),