Reimplement Maps and Sets in JS

src/macros.py

Index: src/macros.py
diff --git a/src/macros.py b/src/macros.py
index 93a5563c19ddaa7e0afcea891993afd722c753ba..a462f804a0a4adc43d6f1cff6911fd0d2db19e1e 100644
--- a/src/macros.py
+++ b/src/macros.py
@@ -272,6 +272,26 @@ const ITERATOR_KIND_KEYS = 1;
 const ITERATOR_KIND_VALUES = 2;
 const ITERATOR_KIND_ENTRIES = 3;
 
+# Needs prefixing
+const NUMBER_OF_BUCKETS_INDEX = 0;
+const NUMBER_OF_ELEMENTS_INDEX = 1;
+const NUMBER_OF_DELETED_ELEMENTS_INDEX = 2;
+const HASH_TABLE_START_INDEX = 3;
+const NOT_FOUND = -1;
+# For sets
+const SET_CHAIN_OFFSET = 1;
+const MAP_CHAIN_OFFSET = 2;
+
+macro SET_ENTRY_TO_INDEX(entry, numBuckets) = (3 + numBuckets + (entry << 1));
+macro SET_KEY_AT(table, entry, numBuckets) = (%_FixedArrayGet(table, SET_ENTRY_TO_INDEX(entry, numBuckets)));
+macro SET_CHAIN_AT(table, entry, numBuckets) = (%_FixedArrayGet(table, SET_ENTRY_TO_INDEX(entry, numBuckets) + 1));
+
+# TODO(adamk): Need to make multiplications not create HeapNumbers
+macro MAP_ENTRY_TO_INDEX(entry, numBuckets) = (3 + numBuckets + ((entry * 3) | 0));
+macro MAP_KEY_AT(table, entry, numBuckets) = (%_FixedArrayGet(table, MAP_ENTRY_TO_INDEX(entry, numBuckets)));
+macro MAP_VALUE_AT(table, entry, numBuckets) = (%_FixedArrayGet(table, MAP_ENTRY_TO_INDEX(entry, numBuckets) + 1));
+macro MAP_CHAIN_AT(table, entry, numBuckets) = (%_FixedArrayGet(table, MAP_ENTRY_TO_INDEX(entry, numBuckets) + 2));
+
 # Check whether debug is active.
 const DEBUG_IS_ACTIVE = (%_DebugIsActive() != 0);
 macro DEBUG_IS_STEPPING(function) = (%_DebugIsActive() != 0 && %DebugCallbackSupportsStepping(function));