feat(gen&zecall): add function support

internal/zecall/zecall_stub.go

@@ -0,0 +1,15 @@
+//go:build !linux && !windows
+
+package zecall
+
+// Register a process for calling. For generated init only. Not thread-safe.
+func Register(string) error {
+	return ErrNotImplemented
+}
+
+// Syscall invokes a registered proc by name. For generated call only.
+// The go:uintptrescapes directive tells the compiler that args may contain
+// pointers converted to uintptr, so the GC will keep them alive during the call.
+func Syscall(name string, args ...uintptr) (uintptr, uintptr, error) {
+	return 0, 0, ErrNotImplemented
+}