xdiff: move stdint.h to xdiff.h

It's more correct to put it in xdiff.h since that file actually uses int64_t
etc and xdiff.h is included by xinclude.h.

This should fix the oss-fuzz build. Thanks durin42 for discovering the
issue.

Test Plan:
`make local` and xdiff related tests still work.

Differential Revision: https://phab.mercurial-scm.org/D2848

mercurial/thirdparty/xdiff/xdiff.h

@@ -29,6 +29,14 b' extern "C" {'
 
 #include <stddef.h> /* size_t */
 
+#if !defined(_MSC_VER) || _MSC_VER >= 1600
+#include <stdint.h>
+#else
+/* prior to Visual Studio 2010 */
+typedef long long int64_t;
+typedef unsigned long long uint64_t;
+#endif
+
 /* xpparm_t.flags */
 #define XDF_NEED_MINIMAL (1 << 0)
 

mercurial/thirdparty/xdiff/xinclude.h

@@ -24,13 +24,6 b''
 #define XINCLUDE_H
 
 #include <ctype.h>
-#if !defined(_MSC_VER) || _MSC_VER >= 1600
-#include <stdint.h>
-#else
-/* prior to Visual Studio 2010 */
-typedef long long int64_t;
-typedef unsigned long long uint64_t;
-#endif
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>