Multiple fixes for 64 bit sections

This changeset attempts to fix a few problems when giving using
the high 32bits of a 64bit section offset. There are likely more
issues (or perhaps regressions) lurking in the muck here. In general,
this moves a few data type declarations to use uplong.  Also, add
support for 64bit mingw32 building under cygwin.  Because native
types are used for 64 bit offsets, this won't fix challenges with
cross compiling from 32bit -> 64bit.

Tested under cygwin, against binary compiled with
-Wl,-Ttext=0xffffff8000000000

Signed-off-by: Andrew Mulbrook <andrew262@gmail.com>

configure

@@ -154,6 +154,8 @@ for opt do
   ;;
   --enable-cygwin) mingw32="yes" ; cygwin="yes" ; cross_prefix="mingw32-" ; cpu=x86
   ;;
+  --enable-cygwin64) mingw32="yes" ; cygwin="yes" ; cross_prefix="x86_64-w64-mingw32-" ; cpu="x86-64"
+  ;;
   --enable-cross) build_cross="yes"
   ;;
   --disable-static) disable_static="yes"
@@ -431,14 +433,18 @@ if test "$noldl" = "yes" ; then
   echo "CONFIG_NOLDL=yes" >> config.mak
 fi
 if test "$mingw32" = "yes" ; then
-  echo "CONFIG_WIN32=yes" >> config.mak
-  echo "#define CONFIG_WIN32 1" >> $TMPH
+  if test "$cpu" = "x86-64" ; then
+    echo "CONFIG_WIN64=yes" >> config.mak
+    echo "#define CONFIG_WIN64 1" >> $TMPH
+  else
+    echo "CONFIG_WIN32=yes" >> config.mak
+    echo "#define CONFIG_WIN32 1" >> $TMPH
+  fi
 fi
 if test "$cygwin" = "yes" ; then
   echo "#ifndef _WIN32" >> $TMPH
   echo "#define _WIN32" >> $TMPH
   echo "#endif" >> $TMPH
-  echo "AR=ar" >> config.mak
 fi
 if test "$bigendian" = "yes" ; then
   echo "WORDS_BIGENDIAN=yes" >> config.mak