Add a new script operator, PROVIDE, to define a symbol only if it
is needed.
* ldgram.y (PROVIDE): New token.
(assignment): Accept PROVIDE.
* ldlex.l (PROVIDE): New token.
* ldexp.h (node_type): Add etree_provide to node_class enum.
(exp_provide): Declare.
* ldexp.c (exp_fold_tree): Handle etree_provide.
(exp_provide): New function.
(exp_print_tree): Handle etree_provide.
* ld.texinfo: Document PROVIDE.
bfd too #.
* ldexp.c, ldlang.c: now build memory shape tree in obstacks
rather than with raw malloc, makes it easier to track where memory
is going.
* ldsym.h, ldsym.c: create obstack for all global symbols too.
* ldwrite.c (ldwrite): moved malloc so only used when needed.
* sa29200-sc.sh: added support for .lit, data1 and data2 sections.
