Fixed another occurrence of NewFileInputStream.

Author: davesisson

runtime-testsuite/test/org/antlr/v4/test/runtime/go/BaseGoTest.java

@@ -674,6 +674,7 @@ protected void writeParserTestFile(String parserName, String lexerName,
 				"import (\n"
 				+"	\"github.com/antlr/antlr4/runtime/Go/antlr\"\n"
 				+"	\"./parser\"\n"
+				+"	\"fmt\"\n"
 				+"	\"os\"\n"
 				+")\n"
 				+ "\n"
@@ -738,7 +739,11 @@ protected void writeLexerTestFile(String lexerName, boolean showDFA) {
 				+ ")\n"
 				+ "\n"
 				+ "func main() {\n"
-				+ "	input := antlr.NewFileStream(os.Args[1])\n"
+				+ "	input, err := antlr.NewFileStream(os.Args[1])\n"
+				+ "     if err != nil {\n"
+				+ "     	fmt.Printf(\"Failed to find file: %v\", err)\n"
+				+ "     	return\n"
+				+ "     }\n"
 				+ "	lexer := parser.New<lexerName>(input)\n"
 				+ "	stream := antlr.NewCommonTokenStream(lexer,0)\n"
 				+ "	stream.Fill()\n"