bug-1593265 Fixed pt-archiver deletes wrong rows

In the case we are trying to migrate a table with no PK nor an unique
key, pt-archiver was failing to select the correct rows for deletion.
This fix implemented here is to add ALL columns in the WHERE clause of
the DELETE command. This way, we are deleting only the exact same row we
just migrated but using columns instead of an index.

bin/pt-archiver

@@ -3201,7 +3201,7 @@ sub generate_del_stmt {
    my $index = $tp->find_best_index($tbl, $args{index});
    die "Cannot find an ascendable index in table" unless $index;
 
-   if ( $index ) {
+   if ( $index && $tbl->{keys}->{$index}->{is_unique}) {
       @del_cols = @{$tbl->{keys}->{$index}->{cols}};
    }
    else {

bin/pt-online-schema-change

@@ -3052,7 +3052,7 @@ sub generate_del_stmt {
    my $index = $tp->find_best_index($tbl, $args{index});
    die "Cannot find an ascendable index in table" unless $index;
 
-   if ( $index ) {
+   if ( $index && $tbl->{keys}->{$index}->{is_unique}) {
       @del_cols = @{$tbl->{keys}->{$index}->{cols}};
    }
    else {

bin/pt-table-checksum

@@ -4901,7 +4901,7 @@ sub generate_del_stmt {
    my $index = $tp->find_best_index($tbl, $args{index});
    die "Cannot find an ascendable index in table" unless $index;
 
-   if ( $index ) {
+   if ( $index && $tbl->{keys}->{$index}->{is_unique}) {
       @del_cols = @{$tbl->{keys}->{$index}->{cols}};
    }
    else {

bin/pt-table-sync

@@ -6480,7 +6480,7 @@ sub generate_del_stmt {
    my $index = $tp->find_best_index($tbl, $args{index});
    die "Cannot find an ascendable index in table" unless $index;
 
-   if ( $index ) {
+   if ( $index && $tbl->{keys}->{$index}->{is_unique}) {
       @del_cols = @{$tbl->{keys}->{$index}->{cols}};
    }
    else {