Add function to test whether function is exported in wasm blob (#9093)

* Add function to test whether function is exported in wasm blob

* Address Feedback

* Update based on feedback

substrate/client/executor/common/src/runtime_blob/runtime_blob.rs

@@ -81,6 +81,15 @@ impl RuntimeBlob {
 		export_mutable_globals(&mut self.raw_module, "exported_internal_global");
 	}
 
+	/// Perform an instrumentation that makes sure that a specific function `entry_point` is exported
+	pub fn entry_point_exists(&self, entry_point: &str) -> bool {
+		self.raw_module.export_section().map(|e| {
+			e.entries()
+			.iter()
+			.any(|e| matches!(e.internal(), Internal::Function(_)) && e.field() == entry_point)
+		}).unwrap_or_default()
+	}
+
 	/// Returns an iterator of all globals which were exported by [`expose_mutable_globals`].
 	pub(super) fn exported_internal_global_names<'module>(
 		&'module self,