add script to set up EC2 storage-optimized instance store for benchmarking (#6350)

Been using this all the time in
https://github.com/neondatabase/neon/pull/6214

Part of https://github.com/neondatabase/neon/issues/5771

Should consider this in https://github.com/neondatabase/neon/issues/6297

scripts/ps_ec2_setup_instance_store

@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+
+# This script sets up an ext4 partition on an EC2 storage-optimized instance's instance store volume.
+# Unix permission/ownership is set to the calling user (the script does sudo internally.)
+#
+# It's intentionally not idempotent; don't take on that complexity in a bash script.
+
+set -euo pipefail
+set -x
+
+# This seems crude, but, apparently instance store NVMe volumes aren't exposed in the in instance metadata block-device-mapping.
+# https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/block-device-mapping-concepts.html#bdm-instance-metadata
+if [ "$(cat /sys/class/block/nvme1n1/device/model)" != "Amazon EC2 NVMe Instance Storage        " ]; then
+    echo "nvme1n1 is not Amazon EC2 NVMe Instance Storage: '$(cat /sys/class/block/nvme1n1/device/model)'"
+    exit 1
+fi
+
+# NB: we DO NOT warm up all the blocks on the drive as recommended by https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/disk-performance.html
+# The reason is that we don't do that in production either.
+
+# do all the on-disk initialization work now instead of a background kernel thread
+# so that we're ready for benchmarking right after this line
+sudo mkfs.ext4 -E lazy_itable_init=0,lazy_journal_init=0  /dev/nvme1n1
+
+MOUNTPOINT=/instance_store
+sudo mkdir "$MOUNTPOINT"
+sudo mount /dev/nvme1n1 "$MOUNTPOINT"
+sudo chown -R "$(id -u)":"$(id -g)" "$MOUNTPOINT"
+
+TEST_OUTPUT="$MOUNTPOINT/test_output"
+mkdir "$TEST_OUTPUT"
+
+NEON_REPO_DIR="$MOUNTPOINT/repo_dir"
+mkdir "$NEON_REPO_DIR"
+
+cat <<EOF
+SETUP COMPLETE
+
+To run your local neon.git build on the instance store volume,
+run the following commands from the top of the neon.git checkout
+
+    # test suite run
+    export TEST_OUTPUT="$TEST_OUTPUT"
+    DEFAULT_PG_VERSION=15 BUILD_TYPE=release ./scripts/pytest test_runner/performance/test_latency.py
+
+    # for interactive use
+    export NEON_REPO_DIR="$NEON_REPO_DIR"
+    cargo build_testing --release
+    ./target/release/neon_local init --force empty-dir-ok
+EOF
+
+