Add some extra Cygwin targets as aliases for Cygwin-x86

Cygwin was used for x86 before, so let's keep it around for those who
still use it (it make Configure reconf possible).
Cygwin-i[3456]86 for those that might generate and pass a target name
directly to Configure.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Configurations/10-main.conf

@@ -1251,6 +1251,23 @@
         shared_ldflag    => "-shared",
         shared_extension => ".dll.a",
     },
+    # Backward compatibility for those using this target
+    "Cygwin" => {
+	inherit_from     => [ "Cygwin-x86" ]
+    },
+    # In case someone constructs the Cygwin target name themself
+    "Cygwin-i386" => {
+	inherit_from     => [ "Cygwin-x86" ]
+    },
+    "Cygwin-i486" => {
+	inherit_from     => [ "Cygwin-x86" ]
+    },
+    "Cygwin-i586" => {
+	inherit_from     => [ "Cygwin-x86" ]
+    },
+    "Cygwin-i686" => {
+	inherit_from     => [ "Cygwin-x86" ]
+    },
 
 #### NetWare from David Ward (dsward@novell.com)
 # requires either MetroWerks NLM development tools, or gcc / nlmconv