8238388: libj2gss/NativeFunc.o "multiple definition" link errors with…

… GCC10

Fixed libj2gss link errors caused by GCC10 default -fno-common

Reviewed-by: weijun

src/java.security.jgss/share/native/libj2gss/NativeFunc.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -27,6 +27,9 @@
 #include <stdlib.h>
 #include "NativeFunc.h"
 
+/* global GSS function table */
+GSS_FUNCTION_TABLE_PTR ftab;
+
 /* standard GSS method names (ordering is from mapfile) */
 static const char RELEASE_NAME[]                = "gss_release_name";
 static const char IMPORT_NAME[]                 = "gss_import_name";

src/java.security.jgss/share/native/libj2gss/NativeFunc.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -277,6 +277,6 @@ typedef struct GSS_FUNCTION_TABLE {
 typedef GSS_FUNCTION_TABLE *GSS_FUNCTION_TABLE_PTR;
 
 /* global GSS function table */
-GSS_FUNCTION_TABLE_PTR ftab;
+extern GSS_FUNCTION_TABLE_PTR ftab;
 
 #endif