Revert "To be investigated: restore cxa_pure_virtual"

This reverts commit 68651bc.

cores/arduino/abi.cpp

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2024 Arduino SA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdlib.h>
+
+extern "C" void __cxa_pure_virtual(void) __attribute__ ((__noreturn__));
+extern "C" void __cxa_deleted_virtual(void) __attribute__ ((__noreturn__));
+
+namespace std {
+  [[gnu::weak, noreturn]] void terminate() {
+    abort();
+  }
+}
+
+void __cxa_pure_virtual(void) {
+  std::terminate();
+}
+
+void __cxa_deleted_virtual(void) {
+  std::terminate();
+}

cores/arduino/new.cpp

@@ -6,8 +6,6 @@
 
 #include "new.h"
 
-extern "C" void __cxa_pure_virtual() {}
-
 // The C++ spec dictates that allocation failure should cause the
 // (non-nothrow version of the) operator new to throw an exception.
 // Since we expect to have exceptions disabled, it would be more