[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/sysfs/futimens_linux.go

@@ -0,0 +1,49 @@
+//go:build !tinygo
+
+package sysfs
+
+import (
+	"syscall"
+	"unsafe"
+	_ "unsafe"
+
+	experimentalsys "github.com/tetratelabs/wazero/experimental/sys"
+)
+
+const (
+	_AT_FDCWD   = -0x64
+	_UTIME_OMIT = (1 << 30) - 2
+)
+
+func utimens(path string, atim, mtim int64) experimentalsys.Errno {
+	times := timesToTimespecs(atim, mtim)
+	if times == nil {
+		return 0
+	}
+
+	var flags int
+	var _p0 *byte
+	_p0, err := syscall.BytePtrFromString(path)
+	if err == nil {
+		err = utimensat(_AT_FDCWD, uintptr(unsafe.Pointer(_p0)), times, flags)
+	}
+	return experimentalsys.UnwrapOSError(err)
+}
+
+// On linux, implement futimens via utimensat with the NUL path.
+func futimens(fd uintptr, atim, mtim int64) experimentalsys.Errno {
+	times := timesToTimespecs(atim, mtim)
+	if times == nil {
+		return 0
+	}
+	return experimentalsys.UnwrapOSError(utimensat(int(fd), 0 /* NUL */, times, 0))
+}
+
+// utimensat is like syscall.utimensat special-cased to accept a NUL string for the path value.
+func utimensat(dirfd int, strPtr uintptr, times *[2]syscall.Timespec, flags int) (err error) {
+	_, _, e1 := syscall.Syscall6(syscall.SYS_UTIMENSAT, uintptr(dirfd), strPtr, uintptr(unsafe.Pointer(times)), uintptr(flags), 0, 0)
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}