x86_64-xlate.pl: new gas requires sign extention in lea instruction.

This resolves md5-x86_64.pl and sha1-x86_64.pl bugs, but without modifying
the code.
PR: 2094,2095

crypto/perlasm/x86_64-xlate.pl

@@ -241,8 +241,9 @@ my %globals;
 
 	if ($gas) {
 	    # Solaris /usr/ccs/bin/as can't handle multiplications
-	    # in $self->{label}
-	    $self->{label} =~ s/(?<![0-9a-f])(0[x0-9a-f]+)/oct($1)/egi;
+	    # in $self->{label}, new gas requires sign extension...
+	    use integer;
+	    $self->{label} =~ s/(?<![0-9a-f])(0[x0-9a-f]+)/oct($1)<<32>>32/egi;
 	    $self->{label} =~ s/([0-9]+\s*[\*\/\%]\s*[0-9]+)/eval($1)/eg;
 	    $self->{label} =~ s/^___imp_/__imp__/   if ($flavour eq "mingw64");