[Chapel Merge] Improve oversubscribedArrayAlloc test for configs

Branch: refs/heads/main
Revision: b6bc7e3
Author: ronawho
Link: Unavailable
Log Message:

Merge pull request #19353 from ronawho/fix-oversubscribedArrayAlloc-test

Improve oversubscribedArrayAlloc test for configs using a fixed heap

This test attempts to use a large fraction of memory to stress test
array allocations. However, it was trying to use a fraction of physical
memory, which can be much larger than what we can actually allocate when
using a fixed heap with CHPL_RT_MAX_HEAP_SIZE set lower, which we do
sometimes to speed up testing.

Base the amount of memory used on the heap size if one is used to avoid
this issue.

Part of https://github.com/Cray/chapel-private/issues/3147

Modified Files:
M test/runtime/configMatters/comm/oversubscribedArrayAlloc.chpl

Compare: https://github.com/chapel-lang/chapel/compare/8ee5a1d4a72a...b6bc7e3fabe2