Search for system name in CHOST instead of trying to extract it.

configure

@@ -32,7 +32,7 @@ fi
 
 # set command prefix for cross-compilation
 if [ -n "${CHOST}" ]; then
-    uname="`echo "${CHOST}" | sed -e 's/^[^-]*-\([^-]*\)$/\1/' -e 's/^[^-]*-[^-]*-\([^-]*\)$/\1/' -e 's/^[^-]*-[^-]*-\([^-]*\)-.*$/\1/'`"
+    uname=${CHOST}
     CROSS_PREFIX="${CHOST}-"
 fi
 
@@ -220,14 +220,14 @@ if test "$gcc" -eq 1 && ($cc -c $test.c) >> configure.log 2>&1; then
     uname=`(uname -s || echo unknown) 2>/dev/null`
   fi
   case "$uname" in
-  Linux* | linux* | GNU | GNU/* | solaris*)
+  Linux* | linux* | *-linux* | GNU | GNU/* | solaris*)
         LDSHARED=${LDSHARED-"$cc -shared -Wl,-soname,libz.so.1,--version-script,${SRCDIR}zlib.map"} ;;
   *BSD | *bsd* | DragonFly)
         LDSHARED=${LDSHARED-"$cc -shared -Wl,-soname,libz.so.1,--version-script,${SRCDIR}zlib.map"}
         LDCONFIG="ldconfig -m" ;;
-  CYGWIN* | Cygwin* | cygwin* | OS/2*)
+  CYGWIN* | Cygwin* | cygwin* | *-cygwin* | OS/2*)
         EXE='.exe' ;;
-  MINGW* | mingw*)
+  MINGW* | mingw* | *-mingw*)
         rm -f $test.[co] $test $test$shared_ext
         echo "If this doesn't work for you, try win32/Makefile.gcc." | tee -a configure.log
         LDSHARED=${LDSHARED-"$cc -shared"}
@@ -246,7 +246,7 @@ if test "$gcc" -eq 1 && ($cc -c $test.c) >> configure.log 2>&1; then
                  shared_ext='.sl'
                  SHAREDLIB='libz.sl' ;;
          esac ;;
-  Darwin* | darwin*)
+  Darwin* | darwin* | *-darwin*)
              shared_ext='.dylib'
              SHAREDLIB=libz$shared_ext
              SHAREDLIBV=libz.$VER$shared_ext