parse.y (parser_initialize): avoid redundant zero-ing

TypedData_Make_Struct already initializes fields to zero by default,
so there's no need to waste code re-zeroing them.

Size reduction on 32-bit x86:

  text    data     bss     dec     hex filename
 187231    2372      80  189683   2e4f3 parse.o.before
 186939    2372      80  189391   2e3cf parse.o

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51304 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Mon Jul 20 15:04:30 2015  Eric Wong  <e@80x24.org>
+
+	* parse.y (parser_initialize): avoid redundant zero-ing
+
 Mon Jul 20 12:12:05 2015  Eric Wong  <e@80x24.org>
 
 	* parse.y (struct parser_params): pack: 88 => 256 bytes on 64-bit

parse.y

@@ -10547,46 +10547,14 @@ internal_id_gen(struct parser_params *parser)
 static void
 parser_initialize(struct parser_params *parser)
 {
-    parser->eofp = 0;
-
-    parser->parser_lex_strterm = 0;
-    parser->parser_cond_stack = 0;
-    parser->parser_cmdarg_stack = 0;
-    parser->parser_paren_nest = 0;
-    parser->parser_lpar_beg = 0;
-    parser->parser_brace_nest = 0;
-    parser->parser_in_single = 0;
-    parser->parser_in_def = 0;
-    parser->parser_in_defined = 0;
-    parser->parser_in_kwarg = 0;
-    parser->parser_compile_for_eval = 0;
-    parser->parser_tokenbuf = NULL;
-    parser->parser_tokidx = 0;
-    parser->parser_toksiz = 0;
-    parser->parser_heredoc_end = 0;
+    /* note: we rely on TypedData_Make_Struct to set most fields to 0 */
     parser->parser_command_start = TRUE;
-    parser->parser_deferred_nodes = 0;
-    parser->parser_lex_pbeg = 0;
-    parser->parser_lex_p = 0;
-    parser->parser_lex_pend = 0;
-    parser->parser_lvtbl = 0;
-    parser->parser_ruby__end__seen = 0;
-    parser->parser_ruby_sourcefile = 0;
     parser->parser_ruby_sourcefile_string = Qnil;
-    parser->cur_arg = 0;
-#ifndef RIPPER
-    parser->parser_eval_tree_begin = 0;
-    parser->parser_eval_tree = 0;
-#else
+#ifdef RIPPER
     parser->delayed = Qnil;
-
     parser->result = Qnil;
     parser->parsing_thread = Qnil;
     parser->toplevel_p = TRUE;
-    parser->error_p = FALSE;
-#endif
-#ifdef YYMALLOC
-    parser->heap = NULL;
 #endif
     parser->enc = rb_utf8_encoding();
 }