Restrict symbol version map to global symbols

ld.lld-17 fails to link when symbols such as

    ld.lld: error: version script assignment of 'SUNWprivate_1.1' to
    symbol '_ZTVZ21WB_HandshakeWalkStackE16TraceSelfClosure' failed:
    symbol not defined

    ld.lld: error: version script assignment of 'SUNWprivate_1.1' to
    symbol '_ZTVZ24WB_HandshakeReadMonitorsE19ReadMonitorsClosure'
    failed: symbol not defined

    ld.lld: error: version script assignment of 'SUNWprivate_1.1' to
    symbol '_ZTVZ26WB_AsyncHandshakeWalkStackE16TraceSelfClosure'
    failed: symbol not defined

are listed in the version map. nm indicates these symbols are defined as
local symbols. Remove them from the version map to resolve the issues.

make/hotspot/lib/JvmMapfile.gmk

@@ -53,7 +53,7 @@ endif
 # platform dependent.
 
 ifeq ($(call isTargetOs, linux), true)
-  DUMP_SYMBOLS_CMD := $(NM) $(NMFLAGS) --defined-only *$(OBJ_SUFFIX)
+  DUMP_SYMBOLS_CMD := $(NM) $(NMFLAGS) --defined-only --extern-only *$(OBJ_SUFFIX)
   ifneq ($(FILTER_SYMBOLS_PATTERN), )
     FILTER_SYMBOLS_PATTERN := $(FILTER_SYMBOLS_PATTERN)|
   endif