Apply the rule of 3/5/0 to JByteArrayCritical et al.

Apply the [rule of 3/5/0](https://en.cppreference.com/w/cpp/language/rule_of_three)
to JByteArrayCritical, SimpleBuffer, JBinaryBlob, JIOBlobs.
This ensures that these objects cannot be copied.

Before, if they were copied (e.g., due to being passed as argument to a
function), the destructor would be called twice, which would release the
critical region twice or which may release the critical region while
another part of the code is still using it.

csrc/buffer.h

@@ -598,6 +598,12 @@ class JByteArrayCritical {
     ~JByteArrayCritical();
     unsigned char* get();
 
+#ifdef HAVE_CPP11
+    // deleting copy constructor and copy assignment to satisfy rule of three
+    JByteArrayCritical(const JByteArrayCritical&) = delete;
+    JByteArrayCritical& operator=(const JByteArrayCritical&) = delete;
+#endif
+
 private:
     void* ptr_;
     JNIEnv* env_;
@@ -610,6 +616,12 @@ class SimpleBuffer {
     ~SimpleBuffer();
     uint8_t* get_buffer();
 
+#ifdef HAVE_CPP11
+    // deleting copy constructor and copy assignment to satisfy rule of three
+    SimpleBuffer(const SimpleBuffer&) = delete;
+    SimpleBuffer& operator=(const SimpleBuffer&) = delete;
+#endif
+
 private:
     uint8_t* buffer_;
 };
@@ -623,6 +635,12 @@ class JBinaryBlob {
     ~JBinaryBlob();
     uint8_t* get();
 
+#ifdef HAVE_CPP11
+    // deleting copy constructor and copy assignment to satisfy rule of three
+    JBinaryBlob(const JBinaryBlob&) = delete;
+    JBinaryBlob& operator=(const JBinaryBlob&) = delete;
+#endif
+
 private:
     // The native pointer that is either backed by a direct ByteBuffer or a byte array.
     uint8_t* ptr_;
@@ -649,6 +667,12 @@ class JIOBlobs {
     uint8_t* get_input();
     uint8_t* get_output();
 
+#ifdef HAVE_CPP11
+    // deleting copy constructor and copy assignment to satisfy rule of three
+    JIOBlobs(const JIOBlobs&) = delete;
+    JIOBlobs& operator=(const JIOBlobs&) = delete;
+#endif
+
 private:
     // The native pointers that are either backed by a direct ByteBuffer or a byte array.
     uint8_t* input_ptr_;