Pass a Java String name to GetMethodObjectNode for interop

* Avoids extra j.l.String -> Ruby String -> j.l.String conversion for LookupMethodNode.

Author: eregon

src/main/java/org/truffleruby/language/ImmutableRubyObject.java

@@ -14,7 +14,6 @@
 import org.truffleruby.RubyLanguage;
 import org.truffleruby.cext.ValueWrapper;
 import org.truffleruby.interop.ForeignToRubyArgumentsNode;
-import org.truffleruby.interop.ForeignToRubyNode;
 import org.truffleruby.language.dispatch.DispatchConfiguration;
 import org.truffleruby.language.dispatch.DispatchNode;
 import org.truffleruby.language.dispatch.InternalRespondToNode;
@@ -112,13 +111,11 @@ public boolean isMemberReadable(String name,
     @ExportMessage
     public Object readMember(String name,
             @Cached @Shared("definedNode") InternalRespondToNode definedNode,
-            @Cached ForeignToRubyNode nameToRubyNode,
             @Cached GetMethodObjectNode getMethodObjectNode,
             @Shared("errorProfile") @Cached BranchProfile errorProfile)
             throws UnknownIdentifierException {
         if (definedNode.execute(null, this, name)) {
-            Object rubyName = nameToRubyNode.executeConvert(name);
-            return getMethodObjectNode.execute(null, this, rubyName, DispatchConfiguration.PRIVATE);
+            return getMethodObjectNode.execute(null, this, name, DispatchConfiguration.PRIVATE);
         } else {
             errorProfile.enter();
             throw UnknownIdentifierException.create(name);

src/main/java/org/truffleruby/language/RubyDynamicObject.java

@@ -591,7 +591,7 @@ public Object readMember(String name,
             if (ivarFoundProfile.profile(iVar != null)) {
                 return iVar;
             } else if (definedNode.execute(null, this, name)) {
-                return getMethodObjectNode.execute(null, this, rubyName, DispatchConfiguration.PRIVATE);
+                return getMethodObjectNode.execute(null, this, name, DispatchConfiguration.PRIVATE);
             } else {
                 errorProfile.enter();
                 throw UnknownIdentifierException.create(name);

src/main/java/org/truffleruby/language/methods/LookupMethodNode.java

@@ -40,8 +40,7 @@ public static LookupMethodNode create() {
         return LookupMethodNodeGen.create();
     }
 
-    public abstract InternalMethod execute(Frame frame, RubyClass metaClass, String name,
-            DispatchConfiguration config);
+    public abstract InternalMethod execute(Frame frame, RubyClass metaClass, String name, DispatchConfiguration config);
 
     @Specialization(
             // no need to guard on the context, the metaClass is context-specific