Convert utf8n_to_uvchr() to macro

It was a macro, but had a long-name function as well.  This converts to
using two macros.

Author: khwilliamson

embed.fnc

@@ -3667,8 +3667,7 @@ ARTdmp	|U8 *	|utf8_hop_safe	|NN const U8 *s 			\
 				|NN const U8 * const end
 ARdp	|STRLEN |utf8_length	|NN const U8 *s0			\
 				|NN const U8 *e
-
-AMTdp	|UV	|utf8n_to_uvchr |NN const U8 *s 			\
+ATdmp	|UV	|utf8n_to_uvchr |NN const U8 *s 			\
 				|STRLEN curlen				\
 				|NULLOK STRLEN *retlen			\
 				|const U32 flags

embed.h

@@ -863,6 +863,7 @@
 # define utf8_to_bytes_new_pv(a,b,c)            Perl_utf8_to_bytes_new_pv(aTHX,a,b,c)
 # define utf8_to_bytes_overwrite(a,b)           Perl_utf8_to_bytes_overwrite(aTHX,a,b)
 # define utf8_to_bytes_temp_pv(a,b)             Perl_utf8_to_bytes_temp_pv(aTHX,a,b)
+# define utf8n_to_uvchr                         Perl_utf8n_to_uvchr
 # define utf8n_to_uvchr_error                   Perl_utf8n_to_uvchr_error
 # define utf8n_to_uvchr_msgs                    Perl_utf8n_to_uvchr_msgs
 # define uvchr_to_utf8(a,b)                     Perl_uvchr_to_utf8(aTHX,a,b)

proto.h

@@ -1115,24 +1115,6 @@ warn.
 =for apidoc Amnh||UTF8_WARN_PERL_EXTENDED
 =for apidoc Amnh||UTF8_DISALLOW_PERL_EXTENDED
 
-=cut
-
-Also implemented as a macro in utf8.h
-*/
-
-UV
-Perl_utf8n_to_uvchr(const U8 *s,
-                    STRLEN curlen,
-                    STRLEN *retlen,
-                    const U32 flags)
-{
-    PERL_ARGS_ASSERT_UTF8N_TO_UVCHR;
-
-    return utf8n_to_uvchr_error(s, curlen, retlen, flags, NULL);
-}
-
-/*
-
 =for apidoc utf8n_to_uvchr_error
 
 THIS FUNCTION SHOULD BE USED IN ONLY VERY SPECIALIZED CIRCUMSTANCES.

utf8.c

@@ -154,9 +154,8 @@ typedef enum {
 #define utf8_to_uvchr_buf(s, e, lenp)                                          \
     Perl_utf8_to_uvchr_buf(aTHX_ (const U8 *) (s), (const U8 *) e, lenp)
 
-#define utf8n_to_uvchr(s, len, lenp, flags)                                    \
-                                utf8n_to_uvchr_error(s, len, lenp, flags, 0)
-
+#define Perl_utf8n_to_uvchr(s, len, lenp, flags)                               \
+                          Perl_utf8n_to_uvchr_error(s, len, lenp, flags, 0)
 #define Perl_utf8n_to_uvchr_error(s, len, lenp, flags, errors)                 \
                     Perl_utf8n_to_uvchr_msgs(s, len, lenp, flags, errors, 0)