Support lexical blocks and function bodies that occupy

Support lexical blocks and function bodies that occupy
non-contiguous address ranges.
* addrmap.c, addrmap.h: New files.
* block.h (struct addrmap): New forward declaration.
(struct blockvector): New member, 'map'.
(BLOCKVECTOR_MAP): New accessor macro.
* block.c: #include "addrmap.h"
(blockvector_for_pc_sect): If the blockvector we've found has
an address map, use it instead of searching the blocks.
* buildsym.c: #include "addrmap.h"
(pending_addrmap_obstack, pending_addrmap_interesting): New static
variables.
(really_free_pendings): If we have a pending addrmap, free it too.
(record_block_range): New function.
(make_blockvector): If we have an interesting pending addrmap,
record it in the new blockvector.
(start_symtab, buildsym_init): Assert that there is no pending
addrmap now; we should have cleaned up any addrmaps we'd built
previously.
(end_symtab): If there is a pending addrmap left over that didn't
get included in the blockvector, free it.
* buildsym.h (struct addrmap): New forward declaration.
(record_block_range): New prototype.
* objfiles.c: #include "addrmap.h".
(objfile_relocate): Relocate the blockvector's address map, if
present.
* dwarf2read.c (dwarf2_record_block_ranges): New function.
(read_func_scope, read_lexical_block_scope): Call it.
* Makefile.in (SFILES): Add addrmap.c.
(addrmap_h): New header dependency variable.
(COMMON_OBS): Add addrmap.o.
(addrmap.o): New rule.l
(block.o, objfiles.o, buildsym.o): Depend on $(addrmap_h).

* block.c (blockvector_for_pc, blockvector_for_pc_sect): Return a
pointer to the block, not its index in the blockvector.
(block_for_pc_sect): Use the returned block, instead of looking it
up ourselves.
* block.h (blockvector_for_pc, blockvector_for_pc_sect): Update
declarations.
* breakpoint.c (resolve_sal_pc): Use returned block, instead of
looking it up ourselves.
* stack.c (print_frame_label_vars): Disable function, which
depends on the block's index.

* buildsym.c (finish_block): Return the block we've built.
* buildsym.h (finish_block): Update prototype.

* defs.h (CORE_ADDR_MAX): New constant.