RFR (XS) 8213992: Rename and make DieOnSafepointTimeout the diagnostic option

[Aleksey Shipilev]

RFE:
  https://bugs.openjdk.java.net/browse/JDK-8213992

While the original option was apparently conceived to aid debugging during the VM development, it is
also useful in product builds to terminate VM when it is stuck on safepoint sync. This is sometimes
asked by external people who have fail-overs set up to deal with VM crashes: making VM fail
predictably on errors like this is a plus for them.

David suggested making the option "product", but I don't like it very much: "product" option
suggests this is a production-grade feature and it comes with expectations of support, which is
interesting in itself when product feature crashes the VM. "diagnostic" keeps this mode available in
product builds without the attached notion of support. Users that want fail-fast VM crash can then
use that option on "we know what we are doing" basis.

The name of the option is hopefully aligned with:
  diagnostic AbortVMOnException (existing)
  diagnostic AbortVMOnSafepointTimeout (this one)
  diagnostic AbortVMOnVMOperationTimeout (JDK-8181143)
  diagnostic AbortVMOnCompilationFailure (JDK-8212070)

Fix:

diff -r 9ad663e63da5 -r 132db6e99f77 src/hotspot/share/runtime/globals.hpp
--- a/src/hotspot/share/runtime/globals.hpp	Fri Nov 16 12:02:08 2018 +0100
+++ b/src/hotspot/share/runtime/globals.hpp	Fri Nov 16 13:35:16 2018 +0100
@@ -498,7 +498,7 @@
           "Time out and warn or fail after SafepointTimeoutDelay "          \
           "milliseconds if failed to reach safepoint")                      \
                                                                             \
-  develop(bool, DieOnSafepointTimeout, false,                               \
+  diagnostic(bool, AbortVMOnSafepointTimeout, false,                        \
           "Die upon failure to reach safepoint (see SafepointTimeout)")     \
                                                                             \
   /* 50 retries * (5 * current_retry_count) millis = ~6.375 seconds */      \
diff -r 9ad663e63da5 -r 132db6e99f77 src/hotspot/share/runtime/safepoint.cpp
--- a/src/hotspot/share/runtime/safepoint.cpp	Fri Nov 16 12:02:08 2018 +0100
+++ b/src/hotspot/share/runtime/safepoint.cpp	Fri Nov 16 13:35:16 2018 +0100
@@ -978,9 +978,9 @@
     }
   }

-  // To debug the long safepoint, specify both DieOnSafepointTimeout &
+  // To debug the long safepoint, specify both AbortVMOnSafepointTimeout &
   // ShowMessageBoxOnError.
-  if (DieOnSafepointTimeout) {
+  if (AbortVMOnSafepointTimeout) {
     fatal("Safepoint sync time longer than " INTX_FORMAT "ms detected when executing %s.",
           SafepointTimeoutDelay, VMThread::vm_safepoint_description());
   }

Testing: hotspot/tier1, grepping for DieOnSafepointTimeout usages, jdk-submit (running)

Thanks,
-Aleksey