A template parameter of PODArray named INITIAL_SIZE didn't make its
units clear, which made some callers to erroneously assume that it
specifies the number of elements and not the number of bytes.
Rename it, fix the wrong usages and, where possible, use the
PODArrayWithStackMemory typedef for arrays with inline memory.
* Hardening debug build: more granular memory mappings and ASLR; add memory protection for mark cache and index
* Addition to prev. revision
* Addition to prev. revision
* Addition to prev. revision
Testing data
```
select 'aaaaaaaa','bbbbbbbb','cccccccc','dddddddd','eeeeeeee','ffffffff','gggg','hhh' from numbers(3000000) into outfile '/tmp/test.tsv'
```
Testing command
```
echo "select count() from file('/tmp/test.tsv', CSV, 'a String, b String, c String, d String, e String, f String, g String, h String') where not ignore(e)" | clickhouse-benchmark
```
TSV parser has less overhead than CSV, using it would better unveil the benefits of memcpySmall.
Before
```
QPS: 1.662, RPS: 4985463.906, MiB/s: 603.823, result RPS: 1.662, result MiB/s: 0.000.
0.000% 0.559 sec.
10.000% 0.564 sec.
20.000% 0.568 sec.
30.000% 0.572 sec.
40.000% 0.575 sec.
50.000% 0.581 sec.
60.000% 0.592 sec.
70.000% 0.624 sec.
80.000% 0.639 sec.
90.000% 0.664 sec.
95.000% 0.686 sec.
99.000% 0.711 sec.
99.900% 0.715 sec.
99.990% 0.716 sec.
```
After
```
QPS: 1.861, RPS: 5582303.107, MiB/s: 676.110, result RPS: 1.861, result MiB/s: 0.000.
0.000% 0.510 sec.
10.000% 0.514 sec.
20.000% 0.517 sec.
30.000% 0.521 sec.
40.000% 0.523 sec.
50.000% 0.527 sec.
60.000% 0.530 sec.
70.000% 0.539 sec.
80.000% 0.558 sec.
90.000% 0.584 sec.
95.000% 0.589 sec.
99.000% 0.608 sec.
99.900% 0.655 sec.
99.990% 0.663 sec.
```
