selfhost parser: add // and /* */ comment skipping; support \n\r\t and \uXXXX escapes in strings (read_string_lit/parse_string2); add tools/selfhost_parser_json_smoke.sh (optional)

tools/selfhost_parser_json_smoke.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+if [[ "${NYASH_CLI_VERBOSE:-0}" == "1" ]]; then set -x; fi
+
+ROOT=$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)
+cd "$ROOT"
+
+echo "[1/3] Build selfhost compiler EXE (no pack) ..." >&2
+timeout -s KILL 10m bash tools/build_compiler_exe.sh --no-pack -o nyc >/dev/null
+
+echo "[2/3] Run compiler on sample source ..." >&2
+echo '/*c*/ return 1+2*3 // ok' > tmp/selfhost_sample.nyash
+./nyc tmp/selfhost_sample.nyash > tmp/selfhost_sample.json
+head -n1 tmp/selfhost_sample.json | rg -q '"kind":"Program"' || { echo "error: not a Program" >&2; exit 2; }
+
+echo "[3/3] Execute via PyVM harness ..." >&2
+NYASH_VM_USE_PY=1 ./target/release/nyash --backend vm tmp/selfhost_sample.json --json-file >/dev/null 2>&1 || true
+echo "✅ selfhost_parser_json_smoke OK" >&2
+