This PR changes SoilBasicSerializer to not use a OrderedCollection to…

… store the already seen objects, but instead a SoilObjectTable.

The SoilObjectTable uses an IdentityDictionary. Checking of we have seen an object already is much faster.

fixes #312

src/Soil-Serializer/SoilBasicSerializer.class.st

@@ -24,7 +24,7 @@ SoilBasicSerializer >> basicNextPutSymbol: aSymbol [
 { #category : #initialization }
 SoilBasicSerializer >> initialize [ 
 	super initialize.
-	objectIdTable := OrderedCollection new
+	objectIdTable := SoilObjectTable new
 ]
 
 { #category : #'writing - basic' }