[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/oflag.go

@@ -0,0 +1,38 @@
+package sysfs
+
+import (
+	"os"
+
+	"github.com/tetratelabs/wazero/experimental/sys"
+)
+
+// toOsOpenFlag converts the input to the flag parameter of os.OpenFile
+func toOsOpenFlag(oflag sys.Oflag) (flag int) {
+	// First flags are exclusive
+	switch oflag & (sys.O_RDONLY | sys.O_RDWR | sys.O_WRONLY) {
+	case sys.O_RDONLY:
+		flag |= os.O_RDONLY
+	case sys.O_RDWR:
+		flag |= os.O_RDWR
+	case sys.O_WRONLY:
+		flag |= os.O_WRONLY
+	}
+
+	// Run down the flags defined in the os package
+	if oflag&sys.O_APPEND != 0 {
+		flag |= os.O_APPEND
+	}
+	if oflag&sys.O_CREAT != 0 {
+		flag |= os.O_CREATE
+	}
+	if oflag&sys.O_EXCL != 0 {
+		flag |= os.O_EXCL
+	}
+	if oflag&sys.O_SYNC != 0 {
+		flag |= os.O_SYNC
+	}
+	if oflag&sys.O_TRUNC != 0 {
+		flag |= os.O_TRUNC
+	}
+	return withSyscallOflag(oflag, flag)
+}