In SVN trunk, pcre_refcount.c, the 16-bit pcre_refcount() name is wrong.
Here is the correct version:
#ifdef COMPILE_PCRE8
PCRE_EXP_DEFN int PCRE_CALL_CONVENTION
pcre_refcount(pcre *argument_re, int adjust)
#else
PCRE_EXP_DEFN int PCRE_CALL_CONVENTION
pcre16_refcount(pcre *argument_re, int adjust)
#endif