vec: Simplify use with C++11 range-based 'for'.

It looks cleaner if we can use a vec* directly as a range for the C++11
range-based 'for' loop, without needing to indirect from it, and also works
with null pointers.

The change in cp_parser_late_parsing_default_args is an example of how this
can be used to simplify a simple loop over a vector.  Reverse or subset
iteration will require adding range adaptors.

I deliberately didn't format the new overloads for etags since they are
trivial.

gcc/ChangeLog:

	* vec.h (begin, end): Add overloads for vec*.
	* tree.c (build_constructor_from_vec): Remove *.

gcc/cp/ChangeLog:

	* decl2.c (clear_consteval_vfns): Remove *.
	* pt.c (do_auto_deduction): Remove *.
	* parser.c (cp_parser_late_parsing_default_args): Change loop
	to use range 'for'.

1 files changed, 1 insertions, 5 deletions

diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 103567c..cc3da15 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -30611,9 +30611,6 @@ cp_parser_late_parsing_default_args (cp_parser *parser, tree fn)
     {
       tree default_arg = TREE_PURPOSE (parm);
       tree parsed_arg;
-      vec<tree, va_gc> *insts;
-      tree copy;
-      unsigned ix;
 
       tree parmdecl = parms[i];
       pushdecl (parmdecl);
@@ -30633,8 +30630,7 @@ cp_parser_late_parsing_default_args (cp_parser *parser, tree fn)
       TREE_PURPOSE (parm) = parsed_arg;
 
       /* Update any instantiations we've already created.  */
-      for (insts = DEFPARSE_INSTANTIATIONS (default_arg), ix = 0;
-	   vec_safe_iterate (insts, ix, &copy); ix++)
+      for (tree copy : DEFPARSE_INSTANTIATIONS (default_arg))
 	TREE_PURPOSE (copy) = parsed_arg;
     }