[JDK 11] RFR: (XS) 8193364: verify_special_jvm_flags should not cause an assertion failure when version is bumped

[David Holmes]

Bug: https://bugs.openjdk.java.net/browse/JDK-8193364
webrev: http://cr.openjdk.java.net/~dholmes/8193364/webrev/

verify_special_jvm_flags operates only in debug builds and sanity checks 
the entries in the deprecated/obsoleted/expired/aliased tables. In 
addition it detects whether we have not yet removed the global variables 
for flags that are obsolete/expired, and issues a warning. In the latter 
case though it also returns false and causes the assertion to fail. This 
make it impossible to bump the JDK version without dealing with every 
flag en-masse.

We should issue the warnings but not fail the assert in these cases.

--- old/src/hotspot/share/runtime/arguments.cpp	2017-12-12 
23:59:14.039718085 -0500
+++ new/src/hotspot/share/runtime/arguments.cpp	2017-12-12 
23:59:11.575576703 -0500
@@ -710,7 +710,6 @@
        if (!version_less_than(JDK_Version::current(), flag.obsolete_in)) {
          if (Flag::find_flag(flag.name) != NULL) {
            warning("Global variable for obsolete special flag entry 
\"%s\" should be removed", flag.name);
-          success = false;
          }
        }
      }
@@ -720,7 +719,6 @@
        if (!version_less_than(JDK_Version::current(), flag.expired_in)) {
          if (Flag::find_flag(flag.name) != NULL) {
            warning("Global variable for expired flag entry \"%s\" 
should be removed", flag.name);
-          success = false;
          }
        }
      }

This need was flagged when we went to JDK 10 (see JDK-8173421) but not 
actioned. We need it now before we bump the version for JDK 11.

Thanks,
David