VHDL-2019: Garbage Collection test exhausts all memory to fail

[bpadalino]

The garbage collection test (tb_030) requires the exhaustion of all memory to fail. For some simulators, the heap can be set and limited. For others, like ghdl, it doesn't allow this from a command line. It's recommended that the amount of heap is limited via ulimit under linux for this test. For systems with a large amount of memory, this test may pass without garbage collection actually being implemented.

I am unsure how to go about doing this within the simulation framework.

[umarcor]

See https://github.com/VHDL/Compliance-Tests/blob/main/run.py#L14-L18. That allows to detect when we are using GHDL and conditionally do check_call(['ulimit', '-m', ...]).