The special flag table lists the following C1 flags, all of which should be obsolete as of JDK 15 and expired in JDK 16:

+#ifndef COMPILER2
+ // These flags were generally available, but are C2 only, now.
+ { "MaxInlineLevel", JDK_Version::undefined(), JDK_Version::jdk(15), JDK_Version::jdk(16) },
+ { "MaxRecursiveInlineLevel", JDK_Version::undefined(), JDK_Version::jdk(15), JDK_Version::jdk(16) },
+ { "InlineSmallCode", JDK_Version::undefined(), JDK_Version::jdk(15), JDK_Version::jdk(16) },
+ { "MaxInlineSize", JDK_Version::undefined(), JDK_Version::jdk(15), JDK_Version::jdk(16) },
+ { "FreqInlineSize", JDK_Version::undefined(), JDK_Version::jdk(15), JDK_Version::jdk(16) },
+ { "MaxTrivialSize", JDK_Version::undefined(), JDK_Version::jdk(15), JDK_Version::jdk(16) },
+#endif

As we are in JDK 16 these flags have in fact all expired and so the entire section should now be deleted.