[lto] PATCH: change low-level CALL_EXPR representation

[Paolo Bonzini]

Sandra Loosemore wrote:
> Finally!  Here's the change all my previous CALL_EXPR-related hacking 
> was in preparation for.  Any comments or complaints before I commit it?

While reading the patch I noted a few particularly easy cleanups that 
could/should be done, and just to have them written somewhere, here they 
are.  Of course this is not related to committing the patch or not!

- move the call_expr_iterator functions to tree.h as static inlines

- use obstack_copy in temp_copy_call_expr and maybe inline it manually

- remove references to preexpand_calls in CALL_EXPR's comment, operand 2 
is used for the static chain now.

- if you wish, move the documentation from tree.h to tree.c for 
functions that are documented in tree.h (especially for tree_size, 
tree_code_size, tree_operand_length since you already have changes for 
them in lto-branch)

Paolo