[wasm] Refactor function name table and lookup

src/wasm/wasm-function-name-table.h

Index: src/wasm/wasm-function-name-table.h
diff --git a/src/wasm/wasm-function-name-table.h b/src/wasm/wasm-function-name-table.h
index 9b6a2c8875cad4d6174176adea0583c88a362a05..ffee7824137d847b7d2d0f8bade4a372057b98b7 100644
--- a/src/wasm/wasm-function-name-table.h
+++ b/src/wasm/wasm-function-name-table.h
@@ -16,9 +16,8 @@ namespace wasm {
 struct WasmModule;
 
 // Encode all function names of the WasmModule into one ByteArray.
-// Returns undefined if the array length would not fit in an integer value.
-Handle<Object> BuildFunctionNamesTable(Isolate* isolate,
-                                       const WasmModule* module);
+Handle<ByteArray> BuildFunctionNamesTable(Isolate* isolate,
+                                          const WasmModule* module);
 
 // Extract the function name for the given func_index from the function name
 // table.