Enable logging for GC relevant information (#1432)

- call `GC.enable_logging(true)` at start of test suite
- print information about what the GC thinks is the available memory

We've been seeing crashes with Julia 1.10 and nightly, which may be GC
related. Enabling this logging may reveal whether abnormal GC behavior
is involved.

test/runtests.jl

@@ -2,6 +2,28 @@ using AbstractAlgebra
 
 using Test
 
+
+if VERSION >= v"1.8.0"
+  GC.enable_logging(true)
+
+  # print gc settings
+  jlmax = @ccall jl_gc_get_max_memory()::UInt64
+  totalmem = @ccall uv_get_total_memory()::UInt64
+  constrmem = @ccall uv_get_constrained_memory()::UInt64
+  println("Memory:   max: ", Base.format_bytes(jlmax))
+  println("        total: ", Base.format_bytes(totalmem))
+  println("       constr: ", Base.format_bytes(constrmem))
+
+#= FIXME/TODO: in the future we may wish to experiment with limiting the GC heap here
+  if VERSION >= v"1.10.0-"
+    # adjust heap size hint
+    memenv = parse(Int, get(ENV, "OSCARCI_MAX_MEM_GB", "5")) * 2^30
+    println("Setting heap size hint to ", Base.format_bytes(memenv))
+    @ccall jl_gc_set_max_memory(memenv::UInt64)::Cvoid
+  end
+=#
+end
+
 include("Aqua.jl")
 include("rand.jl")
 include("AbstractAlgebra-test.jl")