[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/tetratelabs/wazero/internal/ieee754/ieee754.go

@@ -0,0 +1,29 @@
+package ieee754
+
+import (
+	"encoding/binary"
+	"io"
+	"math"
+)
+
+// DecodeFloat32 decodes a float32 in IEEE 754 binary representation.
+// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#floating-point%E2%91%A2
+func DecodeFloat32(buf []byte) (float32, error) {
+	if len(buf) < 4 {
+		return 0, io.ErrUnexpectedEOF
+	}
+
+	raw := binary.LittleEndian.Uint32(buf[:4])
+	return math.Float32frombits(raw), nil
+}
+
+// DecodeFloat64 decodes a float64 in IEEE 754 binary representation.
+// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#floating-point%E2%91%A2
+func DecodeFloat64(buf []byte) (float64, error) {
+	if len(buf) < 8 {
+		return 0, io.ErrUnexpectedEOF
+	}
+
+	raw := binary.LittleEndian.Uint64(buf)
+	return math.Float64frombits(raw), nil
+}