Add system property for shape/key cache limit.

Author: woess

truffle/src/com.oracle.truffle.api.object/src/com/oracle/truffle/api/object/DynamicObject.java

@@ -346,7 +346,7 @@ static Lookup internalLookup() {
 
     // NODES
 
-    static final int SHAPE_CACHE_LIMIT = 5;
+    static final int SHAPE_CACHE_LIMIT = ObjectStorageOptions.CacheLimit;
 
     /**
      * Gets the value of a property or returns a default value if no such property exists.

truffle/src/com.oracle.truffle.api.object/src/com/oracle/truffle/api/object/ObjectStorageOptions.java

@@ -72,6 +72,9 @@ private ObjectStorageOptions() {
     /** Number of differing, compatible property locations allowed when merging shapes. */
     static final int MaxMergeDiff = Integer.getInteger(OPTION_PREFIX + "MaxMergeDiff", 2);
 
+    /** Number of shapes and keys to cache per access node before rewriting to the generic case. */
+    static final int CacheLimit = Integer.getInteger(OPTION_PREFIX + "CacheLimit", 5);
+
     // Debug options (should be final)
     static final boolean TraceReshape = booleanOption(OPTION_PREFIX + "TraceReshape", false);