cygwin: skip -flto on all cygwins

and revert --enable-auto-image-base. Didn't work even on 64bit.
-flto just move the symbols round too much for 32 relocations.
Invalid relocation. Offset 0x.. at address 0x.. doesn't fit into 32 bits

Author: rurban

Configure

@@ -5743,8 +5743,8 @@ $define)
 esac
 
 : probe for -flto
-case "$myarchname" in
-i686-pc-cygwin) ;;
+case "$osname" in
+cygwin) ;;
 *)
   case "$cc $ccflags $dflt" in
     *-DDEBUGGING*)

Makefile.SH

@@ -75,11 +75,8 @@ true)
 			     -install_name \$(shrpdir)/\$@"
 		;;
 	cygwin*)
-	        shrpldflags="$shrpldflags -Wl,--out-implib=libcperl.dll.a"
-                case $ccflags in
-                    *flto*) shrpldflags="$shrpldflags -Wl,--enable-auto-image-base" ;;
-                    *)      shrpldflags="$shrpldflags -Wl,--image-base,0x52000000" ;;
-                esac
+	        shrpldflags="$shrpldflags -Wl,--out-implib=libcperl.dll.a \
+			     -Wl,--image-base,0x52000000"
 		linklibperl="-L. -lcperl"
 		;;
 	sunos*)

pod/perlcdelta.pod

@@ -404,9 +404,10 @@ Fixed C<boot_Win32CORE> prototype to skip dllexport, fatal with C<-flto>.
 
 Fixed ar for F<Win32CORE.a> by using the gcc liblto plugin.
 
-Skip probing for C<-flto> on 32bit cygwin. This reliably fails to find
-a proper image-base with that many new symbols, the adress space is just
-too small.
+Skip probing for C<-flto> on cygwin. This reliably fails to find a
+proper image-base with that many new symbols, the adress space is just
+too small:
+C<Invalid relocation. Offset 0x.. at address 0x.. doesn't fit into 32 bits>
 
 =back