NOTE: the current sources are up-to-date with PCRE 8.13 plus r661
      from PCRE SVN which fixes collation symbol recognition issue.
      This will be in PCRE 8.20 eventually and then this note can go away.

pcre_internal.h includes the relevant definitions that configure would
make.

--- pcre-7.9/pcre_internal.h	2009-04-11 09:21:17.000000000 +0100
+++ ./pcre_internal.h	2009-06-13 10:45:35.000000000 +0100
@@ -81,6 +81,24 @@
 #endif
 
 
+/* Get the definitions provided by running "configure" */
+
+#include <config.h>
+
+/* and those that are not in R's configure */
+#define HAVE_MEMMOVE 1
+#ifndef LINK_SIZE
+#define LINK_SIZE 2
+#define MATCH_LIMIT 10000000
+#define MATCH_LIMIT_RECURSION MATCH_LIMIT
+#define MAX_NAME_COUNT 10000
+#define MAX_NAME_SIZE 32
+#define NEWLINE 10
+#define POSIX_MALLOC_THRESHOLD 10
+#define SUPPORT_UTF8
+#define SUPPORT_UCP
+#endif
+
 /* Standard C headers plus the external interface definition. The only time
 setjmp and stdarg are used is when NO_RECURSE is set. */