xdiff: use int64 for hash table size

Follow-up of the previous "long" -> "int64" change. Now xdiff only uses int
for return values and small integers (ex. booleans, shifting score, bits in
hash table size, etc) so it should be able to handle large input.

Differential Revision: https://phab.mercurial-scm.org/D2765

mercurial/thirdparty/xdiff/xprepare.c

@@ -70,7 +70,7 b' static int xdl_optimize_ctxs(xdlclassifi'
 static int xdl_init_classifier(xdlclassifier_t *cf, int64_t size, int64_t flags) {
 	cf->flags = flags;
 
-	cf->hbits = xdl_hashbits((unsigned int) size);
+	cf->hbits = xdl_hashbits(size);
 	cf->hsize = 1 << cf->hbits;
 
 	if (xdl_cha_init(&cf->ncha, sizeof(xdlclass_t), size / 4 + 1) < 0) {
@@ -262,7 +262,7 b' static int xdl_prepare_ctx(unsigned int '
 		goto abort;
 
 	{
-		hbits = xdl_hashbits((unsigned int) narec);
+		hbits = xdl_hashbits(narec);
 		hsize = 1 << hbits;
 		if (!(rhash = (xrecord_t **) xdl_malloc(hsize * sizeof(xrecord_t *))))
 			goto abort;

mercurial/thirdparty/xdiff/xutils.c

@@ -141,9 +141,10 b' uint64_t xdl_hash_record(char const **da'
 	return ha;
 }
 
-unsigned int xdl_hashbits(unsigned int size) {
-	unsigned int val = 1, bits = 0;
+unsigned int xdl_hashbits(int64_t size) {
+	int64_t val = 1;
+	unsigned int bits = 0;
 
-	for (; val < size && bits < CHAR_BIT * sizeof(unsigned int); val <<= 1, bits++);
+	for (; val < size && bits < (int64_t) CHAR_BIT * sizeof(unsigned int); val <<= 1, bits++);
 	return bits ? bits: 1;
 }

mercurial/thirdparty/xdiff/xutils.h

@@ -32,7 +32,7 b' void *xdl_cha_alloc(chastore_t *cha);'
 int64_t xdl_guess_lines(mmfile_t *mf, int64_t sample);
 int xdl_recmatch(const char *l1, int64_t s1, const char *l2, int64_t s2);
 uint64_t xdl_hash_record(char const **data, char const *top);
-unsigned int xdl_hashbits(unsigned int size);
+unsigned int xdl_hashbits(int64_t size);