patch 8.0.1717: C89 check causes too much trouble

Problem:    C89 check causes too much trouble.
Solution:   Remove enforcing C89 for now.

src/auto/configure

@@ -4206,8 +4206,6 @@ if test "$GCC" = yes; then
       CFLAGS="$CFLAGS -fno-strength-reduce"
     fi
   fi
-
-    CPPFLAGS="$CPPFLAGS -D_POSIX_C_SOURCE=200809L -D_XOPEN_SOURCE=700"
 fi
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for clang version" >&5
@@ -14434,10 +14432,6 @@ if test "$zOSUnix" = "yes"; then
 	CFLAGS="-D_ALL_SOURCE -Wc,float\(ieee\),dll"
 fi
 
-if test "$GCC" = yes -a "$GUITYPE" != "GTK" -a "X$RUBY_CFLAGS" = "X"; then
-  CFLAGS="$CFLAGS -ansi"
-fi
-
 ac_config_files="$ac_config_files auto/config.mk:config.mk.in"
 
 cat >confcache <<\_ACEOF

src/configure.ac

@@ -61,9 +61,6 @@ if test "$GCC" = yes; then
       CFLAGS="$CFLAGS -fno-strength-reduce"
     fi
   fi
-
-  dnl Declare what standards the code should comply with
-  CPPFLAGS="$CPPFLAGS -D_POSIX_C_SOURCE=200809L -D_XOPEN_SOURCE=700"
 fi
 
 dnl clang-500.2.75 or around has abandoned -f[no-]strength-reduce and issues a
@@ -4403,13 +4400,6 @@ if test "$zOSUnix" = "yes"; then
 	CFLAGS="-D_ALL_SOURCE -Wc,float\(ieee\),dll"
 fi
 
-dnl Declare what standards the code should comply with.
-dnl But not when using GTK, the header files cause all kinds of warnings.
-dnl But not when using Ruby, it needs "inline".
-if test "$GCC" = yes -a "$GUITYPE" != "GTK" -a "X$RUBY_CFLAGS" = "X"; then
-  CFLAGS="$CFLAGS -ansi"
-fi
-
 dnl write output files
 AC_OUTPUT(auto/config.mk:config.mk.in)
 

src/version.c

@@ -762,6 +762,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1717,
 /**/
     1716,
 /**/