8079087: Add support for Cygwin 2.0

Reviewed-by: tbell

common/autoconf/basics_windows.m4

@@ -312,8 +312,8 @@ AC_DEFUN([BASIC_CHECK_PATHS_WINDOWS],
     WINDOWS_ENV_VENDOR='cygwin'
     WINDOWS_ENV_VERSION="$CYGWIN_VERSION"
 
-    CYGWIN_VERSION_OK=`$ECHO $CYGWIN_VERSION | $GREP ^1.7.`
-    if test "x$CYGWIN_VERSION_OK" = x; then
+    CYGWIN_VERSION_OLD=`$ECHO $CYGWIN_VERSION | $GREP -e '^1\.[0-6]'`
+    if test "x$CYGWIN_VERSION_OLD" != x; then
       AC_MSG_NOTICE([Your cygwin is too old. You are running $CYGWIN_VERSION, but at least cygwin 1.7 is required. Please upgrade.])
       AC_MSG_ERROR([Cannot continue])
     fi

common/autoconf/generated-configure.sh

@@ -3878,7 +3878,7 @@ fi
 #CUSTOM_AUTOCONF_INCLUDE
 
 # Do not change or remove the following line, it is needed for consistency checks:
-DATE_WHEN_GENERATED=1426765548
+DATE_WHEN_GENERATED=1430836833
 
 ###############################################################################
 #
@@ -7265,8 +7265,8 @@ $as_echo "$CYGWIN_VERSION" >&6; }
     WINDOWS_ENV_VENDOR='cygwin'
     WINDOWS_ENV_VERSION="$CYGWIN_VERSION"
 
-    CYGWIN_VERSION_OK=`$ECHO $CYGWIN_VERSION | $GREP ^1.7.`
-    if test "x$CYGWIN_VERSION_OK" = x; then
+    CYGWIN_VERSION_OLD=`$ECHO $CYGWIN_VERSION | $GREP -e '^1\.0-6'`
+    if test "x$CYGWIN_VERSION_OLD" != x; then
       { $as_echo "$as_me:${as_lineno-$LINENO}: Your cygwin is too old. You are running $CYGWIN_VERSION, but at least cygwin 1.7 is required. Please upgrade." >&5
 $as_echo "$as_me: Your cygwin is too old. You are running $CYGWIN_VERSION, but at least cygwin 1.7 is required. Please upgrade." >&6;}
       as_fn_error $? "Cannot continue" "$LINENO" 5