MapCache simplification. It is now a FixedArray that maps number of properties to a WeakCell with...

src/contexts.h

Index: src/contexts.h
diff --git a/src/contexts.h b/src/contexts.h
index 716682d2739ed57829cef5eae8ae1289b543735a..8182532039996035798764d6f4fb56f0fd5f8a5c 100644
--- a/src/contexts.h
+++ b/src/contexts.h
@@ -413,13 +413,13 @@ class Context: public FixedArray {
     UNSCOPABLES_SYMBOL_INDEX,
     ARRAY_VALUES_ITERATOR_INDEX,
     GLOBAL_CONTEXT_TABLE_INDEX,
+    MAP_CACHE_INDEX,
 
     // Properties from here are treated as weak references by the full GC.
     // Scavenge treats them as strong references.
     OPTIMIZED_FUNCTIONS_LIST,  // Weak.
     OPTIMIZED_CODE_LIST,       // Weak.
     DEOPTIMIZED_CODE_LIST,     // Weak.
-    MAP_CACHE_INDEX,           // Weak.
     NEXT_CONTEXT_LINK,         // Weak.
 
     // Total number of slots.