RFR (trivial): 8231560: Remove expired flags in JDK 16

[David Holmes]

Bug: https://bugs.openjdk.java.net/browse/JDK-8231560
webrev: http://cr.openjdk.java.net/~dholmes/8231560/webrev/

It is that time of the release again. :)

All expired flags are now removed from the flag table.

Testing:
   - local build
   - full repo grep for the expired flag names
   - checked all flags now reported as unknown

Thanks,
David
-----

-   { "BindGCTaskThreadsToCPUs",       JDK_Version::undefined(), 
JDK_Version::jdk(14), JDK_Version::jdk(16) },
-   { "UseGCTaskAffinity",             JDK_Version::undefined(), 
JDK_Version::jdk(14), JDK_Version::jdk(16) },
-   { "GCTaskTimeStampEntries",        JDK_Version::undefined(), 
JDK_Version::jdk(14), JDK_Version::jdk(16) },
-   { "G1RSetScanBlockSize",           JDK_Version::jdk(14), 
JDK_Version::jdk(15), JDK_Version::jdk(16) },
-   { "UseParallelOldGC",              JDK_Version::jdk(14), 
JDK_Version::jdk(15), JDK_Version::jdk(16) },
-   { "CompactFields",                 JDK_Version::jdk(14), 
JDK_Version::jdk(15), JDK_Version::jdk(16) },
-   { "FieldsAllocationStyle",         JDK_Version::jdk(14), 
JDK_Version::jdk(15), JDK_Version::jdk(16) },
- #ifndef X86
-   { "UseSSE",                        JDK_Version::undefined(), 
JDK_Version::jdk(15), JDK_Version::jdk(16) },
- #endif // !X86
-   { "UseAdaptiveGCBoundary",         JDK_Version::undefined(), 
JDK_Version::jdk(15), JDK_Version::jdk(16) },
-   { "MonitorBound",                  JDK_Version::jdk(14), 
JDK_Version::jdk(15), JDK_Version::jdk(16) },
- #ifdef AARCH64
-   { "UseBarriersForVolatile",        JDK_Version::undefined(), 
JDK_Version::jdk(15), JDK_Version::jdk(16) },
- #endif
-   { "UseLWPSynchronization",         JDK_Version::undefined(), 
JDK_Version::jdk(15), JDK_Version::jdk(16) },
-   { "BranchOnRegister",              JDK_Version::undefined(), 
JDK_Version::jdk(15), JDK_Version::jdk(16) },
-   { "LIRFillDelaySlots",             JDK_Version::undefined(), 
JDK_Version::jdk(15), JDK_Version::jdk(16) },