Add const in five places to move 1 KiB to .rdata

xmlUnicodeBlocks is logically const but was not marked as such. This
fixes that, thus moving it to the read-only data segment.
diff --git a/genUnicode.py b/genUnicode.py
index 56e4e9b..4487eeb 100755
--- a/genUnicode.py
+++ b/genUnicode.py
@@ -267,14 +267,14 @@
 } xmlUnicodeRange;
 
 typedef struct {
-    xmlUnicodeRange *table;
+    const xmlUnicodeRange *table;
     int		    numentries;
 } xmlUnicodeNameTable;
 
 
 static xmlIntFunc *xmlUnicodeLookup(xmlUnicodeNameTable *tptr, const char *tname);
 
-static xmlUnicodeRange xmlUnicodeBlocks[] = {
+static const xmlUnicodeRange xmlUnicodeBlocks[] = {
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 flag = 0