The redundant forward declaration of 'struct real_pcre' before the
typedef was tripping up gtk-doc. Remove it.
/* Types */
-struct real_pcre; /* declaration; the definition is private */
-typedef struct real_pcre pcre;
+typedef struct real_pcre pcre; /* declaration; the definition is private */
/* When PCRE is compiled as a C++ library, the subject pointer type can be
replaced with a custom type. For conventional use, the public interface is a