new sun.misc.Signal("INFO") throws IllegalArgumentException since JDK11

It used to work fine in older versions.

* SIGINFO was available in JDK 8 (jvm_bsd.cpp) but it seems it was accidentally removed during consolidation of the signal list in os_posix.cpp.
* SIGINFO is the only missing signal compared to signal lists in JDK 8.

The fix is simple:
{noformat}
diff --git a/src/hotspot/os/posix/os_posix.cpp b/src/hotspot/os/posix/os_posix.cpp
index 017a107300..cdada0093e 100644
--- a/src/hotspot/os/posix/os_posix.cpp
+++ b/src/hotspot/os/posix/os_posix.cpp
@@ -784,6 +784,9 @@ static const struct {
   { SIGHUP, "SIGHUP" },
   { SIGILL, "SIGILL" },
   { SIGINT, "SIGINT" },
+#ifdef SIGINFO
+ { SIGINFO, "SIGINFO" },
+#endif
 #ifdef SIGIO
   { SIGIO, "SIGIO" },
 #endif
{noformat}