8058322: Zero name_index item of MethodParameters attribute cause MalformedParameterException.

Allow hotspot to report null for 0 parameter_name index in MethodParameters attribute

Backport-of: cba5bd26387dc2ecb31ac8d6bea21bcc01da0cd5

Author: liach

hotspot/src/share/vm/runtime/reflection.cpp

@@ -867,17 +867,16 @@ oop Reflection::new_field(fieldDescriptor* fd, bool intern_name, TRAPS) {
 
 oop Reflection::new_parameter(Handle method, int index, Symbol* sym,
                               int flags, TRAPS) {
-  Handle name;
 
-  // A null symbol here translates to the empty string
+  Handle rh = java_lang_reflect_Parameter::create(CHECK_NULL);
+
   if(NULL != sym) {
-    name = java_lang_String::create_from_symbol(sym, CHECK_NULL);
+    Handle name = java_lang_String::create_from_symbol(sym, CHECK_NULL);
+    java_lang_reflect_Parameter::set_name(rh(), name());
   } else {
-    name = java_lang_String::create_from_str("", CHECK_NULL);
+    java_lang_reflect_Parameter::set_name(rh(), NULL);
   }
 
-  Handle rh = java_lang_reflect_Parameter::create(CHECK_NULL);
-  java_lang_reflect_Parameter::set_name(rh(), name());
   java_lang_reflect_Parameter::set_modifiers(rh(), flags);
   java_lang_reflect_Parameter::set_executable(rh(), method());
   java_lang_reflect_Parameter::set_index(rh(), index);