Add support for limiting overall memory when running decompilations and tools

[s3rvac]

We should add support for limiting the overall memory when running decompilations and tools to prevent issues like #36 and #81 (black screen when decompiling on Windows). On Linux, it is pretty easy to limit virtual memory via ulimit -v, but on Windows, this is not that straightforward.

Our scripts and tools should have a parameter by which one could control the maximal virtual memory (e.g. --max-memory). By default, this should be set to half of the available memory on the system. When a tool has allocated more than this limit, further allocations should fail with std::bad_alloc instead of starting swapping.

Note: We should of course try to reduce the memory requirements of our tools (see e.g. #13). This new parameter represents just a precaution to reduce swapping, and should be taken as such.

[s3rvac]

Implemented in #272.

Details:

• Added a new module memory into retdec::utils, which provides ways of limiting the available memory of the current process (b63d814). Supported platforms are Windows, Linux, and macOS.
• Added new parameters --max-memory and --max-memory-half-ram into retdec-fileinfo (bf0a1c6). By default, there is no memory limit when you run the tool.
• Added new parameters -max-memory and -max-memory-half-ram into retdec-bin2llvmir and retdec-llvmir2hll (a7516cb and 349c595). By default, there is no memory limit when you run the tools.
• Added new parameters --max-memory and --no-memory-limit into retdec-decompiler.sh (23434fa). By default, the script limits the memory of the above tools into half of system RAM to prevent potential black screens (especially on Windows). Use --no-memory-limit to remove this limit.
• Regression tests were added in the issue-270-limiting-overall-memory branch (merge: avast/retdec-regression-tests@0b9c04f).