Remove effectless --enable-gd-native-ttf and USE_GD_IMGSTRTTF

--enable-gd-native-ttf did set USE_GD_IMGSTRTTF, which is otherwise unused
as of commit 8a90aad3 (i.e. PHP 5.5.0), at least.

UPGRADING

@@ -84,6 +84,10 @@ PHP 7.2 UPGRADE NOTES
    . Added extended exif tag support for the following formats: 
      Samsung, DJI, Panasonic, Sony, Pentax, Minolta & Sigma/Foveon.
 
+- GD:
+    . Removed --enable-gd-native-ttf configuration option which was unused as
+      of PHP 5.5.0 anyway.
+
 - Mbstring
   . mb_check_encoding() accepts array parameter. Both key and value
     ecodings are checked recursively.

ext/gd/config.m4

@@ -35,9 +35,6 @@ PHP_ARG_WITH(xpm-dir, for the location of libXpm,
 PHP_ARG_WITH(freetype-dir, for FreeType 2,
 [  --with-freetype-dir[=DIR] GD: Set the path to FreeType 2 install prefix], no, no)
 
-PHP_ARG_ENABLE(gd-native-ttf, whether to enable truetype string function in GD,
-[  --enable-gd-native-ttf  GD: Enable TrueType string function], no, no)
-
 PHP_ARG_ENABLE(gd-jis-conv, whether to enable JIS-mapped Japanese font support in GD,
 [  --enable-gd-jis-conv    GD: Enable JIS-mapped Japanese font support], no, no)
 
@@ -206,7 +203,6 @@ AC_DEFUN([PHP_GD_FREETYPE2],[
 
     PHP_EVAL_INCLINE($FREETYPE2_CFLAGS)
     PHP_EVAL_LIBLINE($FREETYPE2_LIBS, GD_SHARED_LIBADD)
-    AC_DEFINE(USE_GD_IMGSTRTTF, 1, [ ])
     AC_DEFINE(HAVE_LIBFREETYPE,1,[ ])
     AC_DEFINE(ENABLE_GD_TTF,1,[ ])
   else
@@ -214,12 +210,6 @@ AC_DEFUN([PHP_GD_FREETYPE2],[
   fi
 ])
 
-AC_DEFUN([PHP_GD_TTSTR],[
-  if test "$PHP_GD_NATIVE_TTF" = "yes"; then
-    AC_DEFINE(USE_GD_IMGSTRTTF, 1, [ ])
-  fi
-])
-
 AC_DEFUN([PHP_GD_JISX0208],[
   if test "$PHP_GD_JIS_CONV" = "yes"; then
     USE_GD_JIS_CONV=1

ext/gd/config.w32

@@ -71,7 +71,6 @@ if (PHP_GD != "no") {
 /D HAVE_LIBPNG  \
 /D HAVE_XPM  \
 /D HAVE_COLORCLOSESTHWB  \
-/D USE_GD_IMGSTRTTF  \
 /D USE_GD_IOCTX \
 /D MSWIN32 \
 		");