CrawlHashTable: reduce RAM overhead

The RAM overhead for an unused CrawlHash table has been reduced from 32
to 4 (on 32 bit systems), with an increased overhead of 4 bytes for ones
which are used.  This leads to a 35% RAM reduction for item_def
instances with an unused props field.

1 files changed, 13 insertions, 12 deletions

diff --git a/crawl-ref/source/tags.h b/crawl-ref/source/tags.h
index c85796bef9..b843a55329 100644
--- a/crawl-ref/source/tags.h
+++ b/crawl-ref/source/tags.h
@@ -49,18 +49,19 @@ enum tag_major_version
 // the dungeon Lua changes.
 enum tag_minor_version
 {
-    TAG_MINOR_ARTEFACT =  0,     // Turned fixed arts into unrandarts.
-    TAG_MINOR_JIYVA    =  1,     // Added some player bits for Jiyva.
-    TAG_MINOR_ZOT_OPEN =  2,     // Remember whether Zot was opened.
-    TAG_MINOR_JELLY    =  3,     // Remember whether the royal jelly is dead.
-    TAG_ANNOTATE_EXCL  =  4,     // Store exclusion information for annotations.
-    TAG_MINOR_UGLY     =  5,     // More ghost bits for (very) ugly things.
-    TAG_MINOR_ROTTING  =  6,     // Added monster-specific rotting resistance.
-    TAG_MINOR_TRANS    =  7,     // Keep track of cancellable transformations.
-    TAG_MINOR_GITREV   =  8,     // Removed SVN revision and added Git revision.
-    TAG_MINOR_DSTRAITS =  9,     // Pre-calculate demonspawn mutations
-    TAG_MINOR_YOU_PROP = 10,     // Player class has CrawlHashTable
-    TAG_MINOR_VERSION  = 10      // Current version.  (Keep equal to max.)
+    TAG_MINOR_ARTEFACT   =  0,   // Turned fixed arts into unrandarts.
+    TAG_MINOR_JIYVA      =  1,   // Added some player bits for Jiyva.
+    TAG_MINOR_ZOT_OPEN   =  2,   // Remember whether Zot was opened.
+    TAG_MINOR_JELLY      =  3,   // Remember whether the royal jelly is dead.
+    TAG_ANNOTATE_EXCL    =  4,   // Store exclusion information for annotations.
+    TAG_MINOR_UGLY       =  5,   // More ghost bits for (very) ugly things.
+    TAG_MINOR_ROTTING    =  6,   // Added monster-specific rotting resistance.
+    TAG_MINOR_TRANS      =  7,   // Keep track of cancellable transformations.
+    TAG_MINOR_GITREV     =  8,   // Removed SVN revision and added Git revision.
+    TAG_MINOR_DSTRAITS   =  9,   // Pre-calculate demonspawn mutations
+    TAG_MINOR_YOU_PROP   = 10,   // Player class has CrawlHashTable
+    TAG_MINOR_SMALL_HASH = 11,   // Reduced RAM size of CrawlHashTable
+    TAG_MINOR_VERSION    = 11    // Current version.  (Keep equal to max.)
 };