Throws an error when I try to _read a large file
Moved from https://github.com/kaitai-io/kaitai_struct/issues/1196, original by @bulbum.

> Good evening!
> I use Kaitai to handle pcap files. And when I try to load 114 MB log:
> `Pcap p = Pcap.fromFile("material\\log114MB.pcap");`
> it throws 
> ```
> Exception in thread "AWT-EventQueue-0" java.lang.OutOfMemoryError: Java heap space
> 	at com.company.EthernetFrame._read(EthernetFrame.java:65)
> 	at com.company.EthernetFrame.<init>(EthernetFrame.java:41)
> 	at com.company.Pcap$Packet._read(Pcap.java:283)
> 	at com.company.Pcap$Packet.<init>(Pcap.java:266)
> 	at com.company.Pcap._read(Pcap.java:164)
> 	at com.company.Pcap.<init>(Pcap.java:144)
> 	at com.company.Pcap.fromFile(Pcap.java:21)
> 	at com.company.View.toParseFromFile(View.java:180)
> 	at com.company.View.access$100(View.java:27)
> 	at com.company.View$1.mouseReleased(View.java:88)
> ```
> However, when I load a 8 KB file, everything is fine. 
> 
> I tried to increase the max heap size using command line option to JVM. But increasing to some finite max value does not ultimately get rid of the issue.