gc: insert semicolon at EOF if needed

R=ken2, gri
CC=golang-dev
https://golang.org/cl/2208053

src/cmd/gc/lex.c

@@ -1247,13 +1247,8 @@ yylex(void)
 	lx = _yylex();
 	
 	if(curio.nlsemi && lx == EOF) {
-		// if the nlsemi bit is set, we'd be willing to
-		// insert a ; if we saw a \n, but we didn't.
-		// that means the final \n is missing.
-		// complain here, because we can give a
-		// good message.  the syntax error we'd get
-		// otherwise is inscrutable.
-		yyerror("missing newline at end of file");
+		// Treat EOF as "end of line" for the purposes
+		// of inserting a semicolon.
 		lx = ';';
 	}
 

test/eof.go

@@ -0,0 +1,9 @@
+// $G $D/$F.go
+
+// Copyright 2010 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// No newline at the end of this file.
+
+package main