[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_darwin.go

@@ -0,0 +1,51 @@
+package sysfs
+
+import (
+	"syscall"
+	_ "unsafe"
+
+	experimentalsys "github.com/tetratelabs/wazero/experimental/sys"
+)
+
+const (
+	_AT_FDCWD            = -0x2
+	_AT_SYMLINK_NOFOLLOW = 0x0020
+	_UTIME_OMIT          = -2
+)
+
+//go:noescape
+//go:linkname utimensat syscall.utimensat
+func utimensat(dirfd int, path string, times *[2]syscall.Timespec, flags int) error
+
+func utimens(path string, atim, mtim int64) experimentalsys.Errno {
+	times := timesToTimespecs(atim, mtim)
+	if times == nil {
+		return 0
+	}
+	var flags int
+	return experimentalsys.UnwrapOSError(utimensat(_AT_FDCWD, path, times, flags))
+}
+
+func futimens(fd uintptr, atim, mtim int64) experimentalsys.Errno {
+	times := timesToTimespecs(atim, mtim)
+	if times == nil {
+		return 0
+	}
+	_p0 := timesToPtr(times)
+
+	// Warning: futimens only exists since High Sierra (10.13).
+	_, _, e1 := syscall_syscall6(libc_futimens_trampoline_addr, fd, uintptr(_p0), 0, 0, 0, 0)
+	return experimentalsys.UnwrapOSError(e1)
+}
+
+// libc_futimens_trampoline_addr is the address of the
+// `libc_futimens_trampoline` symbol, defined in `futimens_darwin.s`.
+//
+// We use this to invoke the syscall through syscall_syscall6 imported below.
+var libc_futimens_trampoline_addr uintptr
+
+// Imports the futimens symbol from libc as `libc_futimens`.
+//
+// Note: CGO mechanisms are used in darwin regardless of the CGO_ENABLED value
+// or the "cgo" build flag. See /RATIONALE.md for why.
+//go:cgo_import_dynamic libc_futimens futimens "/usr/lib/libSystem.B.dylib"