Add harness for low memory testing

tests/test-failmalloc

@@ -0,0 +1,41 @@
+#!/bin/bash
+set -euo pipefail
+
+# A harness that runs SQLite with the parquet extension in an environment where malloc randomly
+# fails. "Success" is if the logs don't have any C++ exceptions that talk about std::bad_alloc
+
+ensure_failmalloc() {
+  if [ ! -d libfailmalloc ]; then
+    git clone https://github.com/cldellow/libfailmalloc.git
+  fi
+
+  if [ ! -e libfailmalloc/.libs/libfailmalloc.so ]; then
+    cd libfailmalloc
+    ./configure
+    make
+  fi
+}
+
+run_under_low_memory() {
+  start=$(date +%s%3N)
+  set +e
+  env LD_PRELOAD="$here"/libfailmalloc/.libs/libfailmalloc.so FAILMALLOC_PROBABILITY=0.00001 ./test-random &> results.bad_alloc
+  set -e
+  now=$(date +%s%3N)
+  echo "Bailed after $((now-start)) ms"
+  ! grep std::bad_alloc results.bad_alloc
+}
+
+main() {
+  here=$(dirname "${BASH_SOURCE[0]}")
+  here=$(readlink -f "$here")
+  cd "$here"
+
+  ensure_failmalloc
+  # Sometimes we'll exit due to a Python memory issue, so try a few times.
+  for i in {0..10}; do
+    run_under_low_memory
+  done
+}
+
+main "$@"