Show foreign readable non-invocable members for java.lang.Class instances

* Which becomes a useful hint to get the Java type from it.

Author: eregon

spec/truffle/interop/foreign_inspect_to_s_spec.rb

@@ -53,10 +53,10 @@
       end
     end
 
-    describe "Java j.l.Class instance" do
+    describe "Java java.lang.Class instance" do
       it "gives a similar representation to Ruby" do
         foreign = Truffle::Interop.java_type("java.math.BigInteger")[:class]
-        foreign.inspect.should =~ /\A#<Polyglot::ForeignInstantiable\[Java\] java.lang.Class:0x\h+ java.math.BigInteger>\z/
+        foreign.inspect.should =~ /\A#<Polyglot::ForeignInstantiable\[Java\] java.lang.Class:0x\h+ java.math.BigInteger static={...}>\z/
         foreign.to_s.should == "#<Polyglot::ForeignInstantiable[Java] java.math.BigInteger>"
       end
     end

src/main/ruby/truffleruby/core/truffle/interop_operations.rb

@@ -77,7 +77,6 @@ def self.foreign_inspect_nonrecursive(object)
 
         show_members = true
         if Truffle::Interop.java_class?(object) # a java.lang.Class instance, treat it like a regular object
-          show_members = false
           string << " #{Truffle::Interop.to_display_string(object)}"
         end
         if Truffle::Interop.has_array_elements?(object)