seoul: implement heap_free

Avoids the message

cxx: operator delete (void *) called - not implemented. A working implementation is available in the 'stdcxx' library

during a " new ..." which causes exceptions. Happens for seoul in disk.cc

Issue #806

ports/src/vancouver/nova_user_env.cc

@@ -82,7 +82,7 @@ void Logging::panic(const char *format, ...)
 }
 
 
-void *heap_alloc(size_t size)
+static void *heap_alloc(size_t size)
 {
 	void *res = Genode::env()->heap()->alloc(size);
 	if (res)
@@ -92,6 +92,16 @@ void *heap_alloc(size_t size)
 	Genode::sleep_forever();
 }
 
+static void heap_free(void * ptr)
+{
+	if (Genode::env()->heap()->need_size_for_free()) {
+		PWRN("leaking memory");
+		return;
+	}
+
+	Genode::env()->heap()->free(ptr, 0);
+}
+
 
 void *operator new[](size_t size)
 {
@@ -129,6 +139,11 @@ void operator delete[](void *ptr)
 		PWRN("delete[] not implemented");
 }
 
+void operator delete (void * ptr)
+{
+	heap_free(ptr);
+}
+
 
 void do_exit(char const *msg)
 {

ports/src/vancouver/service/memory.h

@@ -16,8 +16,6 @@ struct Aligned {
         Aligned(size_t alignment) : alignment(alignment) {}
 };
 
-void *heap_alloc(size_t size);
-
 void *operator new[](size_t size);
 
 void *operator new[](size_t size, Aligned const alignment);