Don't use exceptions in low-level mem allocator

src/randomx.cpp

@@ -113,6 +113,10 @@ extern "C" {
 				cache = nullptr;
 			}
 		}
+		if (cache && cache->memory == nullptr) {
+			randomx_release_cache(cache);
+			cache = nullptr;
+		}
 
 		return cache;
 	}
@@ -162,6 +166,10 @@ extern "C" {
 				dataset = nullptr;
 			}
 		}
+		if (dataset && dataset->memory == nullptr) {
+			randomx_release_dataset(dataset);
+			dataset = nullptr;
+		}
 
 		return dataset;
 	}