Clear callInfo in this block body

Enumerable#to_a does not take keywords but also was not handling
any incoming callInfo bits. As a result an incoming
CALL_KEYWORD_EMPTY bit can get stuck and propagte through to the
next call. This does not process any kwargs because it is
effectively a block with signature like |a, *b| but whether it
should do more than clearing callInfo is unknown.

Fixes jruby#8382

core/src/main/java/org/jruby/RubyEnumerable.java

@@ -2302,12 +2302,14 @@ public AppendBlockCallback(Ruby runtime, RubyArray result) {
         }
 
         public IRubyObject call(ThreadContext context, IRubyObject[] args, Block block) {
+            ThreadContext.resetCallInfo(context);
             result.append(packEnumValues(context, args));
             return context.nil;
         }
 
         @Override
         public IRubyObject call(ThreadContext context, IRubyObject arg, Block block) {
+            ThreadContext.resetCallInfo(context);
             result.append(arg);
             return context.nil;
         }