[Bug c++/59032] [4.8/4.9 Regression] ICE incrementing vector type

["vries at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59032

--- Comment #4 from vries at gcc dot gnu.org ---
> We already support v=v+1, so it wouldn't be a large extension.

Hmm, indeed. If found some code in cp_builld_binary_op marked with this
comment:
...
  /* In case when one of the operands of the binary operation is
     a vector and another is a scalar -- convert scalar to vector.  */
...

I've tried to do something similar in cp_build_unary_op. Tentative patch:
...
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index bcb8782..0554664 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -5746,7 +5746,38 @@ cp_build_unary_op (enum tree_code code, tree xarg, int
noconvert,
        else
          inc = integer_one_node;

-       inc = cp_convert (argtype, inc, complain);
+       /* In case when the operand of the unary operation is a vector --
+          convert scalar inc to vector.  */
+       if (TREE_CODE (TREE_TYPE (arg)) == VECTOR_TYPE)
+         {
+           enum stv_conv convert_flag;
+           enum tree_code pm_code = ((code == PREINCREMENT_EXPR
+                                      || code == POSTINCREMENT_EXPR)
+                                     ? PLUS_EXPR
+                                     : MINUS_EXPR);
+
+           convert_flag = scalar_to_vector (input_location, pm_code, arg, inc,
+                                            complain & tf_error);
+
+           switch (convert_flag)
+             {
+             case stv_error:
+               return error_mark_node;
+             case stv_firstarg:
+               gcc_unreachable ();
+             case stv_secondarg:
+               {
+                 inc = save_expr (inc);
+                 inc = convert (TREE_TYPE (TREE_TYPE (arg)), inc);
+                 inc = build_vector_from_val (TREE_TYPE (arg), inc);
+                 break;
+               }
+             default:
+               break;
+             }
+         }
+       else
+         inc = cp_convert (argtype, inc, complain);

        /* If 'arg' is an Objective-C PROPERTY_REF expression, then we
           need to ask Objective-C to build the increment or decrement
...