[experiment] add alternative wasm sqlite3 implementation available via build-tag (#2863)

This allows for building GoToSocial with [SQLite transpiled to WASM](https://github.com/ncruces/go-sqlite3) and accessed through [Wazero](https://wazero.io/).

vendor/github.com/ncruces/go-sqlite3/embed/build.sh

@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+cd -P -- "$(dirname -- "$0")"
+
+ROOT=../
+BINARYEN="$ROOT/tools/binaryen-version_117/bin"
+WASI_SDK="$ROOT/tools/wasi-sdk-22.0/bin"
+
+"$WASI_SDK/clang" --target=wasm32-wasi -std=c17 -flto -g0 -O2 \
+	-Wall -Wextra -Wno-unused-parameter -Wno-unused-function \
+	-o sqlite3.wasm "$ROOT/sqlite3/main.c" \
+	-I"$ROOT/sqlite3" \
+	-mexec-model=reactor \
+	-msimd128 -mmutable-globals \
+	-mbulk-memory -mreference-types \
+	-mnontrapping-fptoint -msign-ext \
+	-fno-stack-protector -fno-stack-clash-protection \
+	-Wl,--initial-memory=327680 \
+	-Wl,--stack-first \
+	-Wl,--import-undefined \
+	-D_HAVE_SQLITE_CONFIG_H \
+	-DSQLITE_CUSTOM_INCLUDE=sqlite_opt.h \
+	$(awk '{print "-Wl,--export="$0}' exports.txt)
+
+trap 'rm -f sqlite3.tmp' EXIT
+"$BINARYEN/wasm-ctor-eval" -g -c _initialize sqlite3.wasm -o sqlite3.tmp
+"$BINARYEN/wasm-opt" -g --strip --strip-producers -c -O3 \
+	sqlite3.tmp -o sqlite3.wasm \
+	--enable-simd --enable-mutable-globals --enable-multivalue \
+	--enable-bulk-memory --enable-reference-types \
+	--enable-nontrapping-float-to-int --enable-sign-ext