make runtime compatible with wasm

runtime/internal/clite/syscall/syscall_unix.go

@@ -0,0 +1,55 @@
+//go:build !wasm
+
+package syscall
+
+import "strconv"
+
+type Errno uintptr
+
+func (e Errno) Error() string {
+	if 0 <= int(e) && int(e) < len(errors) {
+		s := errors[e]
+		if s != "" {
+			return s
+		}
+	}
+	return "errno " + strconv.Itoa(int(e))
+}
+
+func (e Errno) Is(target error) bool {
+	switch target {
+	case ErrPermission:
+		return e == EACCES || e == EPERM
+	case ErrExist:
+		return e == EEXIST || e == ENOTEMPTY
+	case ErrNotExist:
+		return e == ENOENT
+	case ErrUnsupported:
+		return e == ENOSYS || e == ENOTSUP || e == EOPNOTSUPP
+	}
+	return false
+}
+
+func (e Errno) Temporary() bool {
+	return e == EINTR || e == EMFILE || e == ENFILE || e.Timeout()
+}
+
+func (e Errno) Timeout() bool {
+	return e == EAGAIN || e == EWOULDBLOCK || e == ETIMEDOUT
+}
+
+// A Signal is a number describing a process signal.
+// It implements the [os.Signal] interface.
+type Signal int
+
+func (s Signal) Signal() {}
+
+func (s Signal) String() string {
+	if 0 <= s && int(s) < len(signals) {
+		str := signals[s]
+		if str != "" {
+			return str
+		}
+	}
+	return "signal " + strconv.Itoa(int(s))
+}