Create and use macros for iterating on symtabs, psymtabs, msymbols.

Create and use macros for iterating on symtabs, psymtabs, msymbols.

* minsyms.c (iterate_over_msymbols):  Remove; clunky and slow.
* symfile.h, symtab.h (iterate_over_msymbols):  Remove prototype
* coffread.c (coff_symfile_read):  iterate_over_symtabs => ALL_SYMTABS.
(patch_opaque_types):  Avoid dummy args and result.
* objfiles.c (have_partial_symbols, have_full_symbols,
have_minimal_symbols):  explicit iteration => ALL_OBJFILES; simplify.
(iterate_over_objfiles, iterate_over_symtabs,
iterate_over_psymtabs):  Remove, clunky and slow.
* objfiles.h:  Replace iterate_over_* prototypes with ALL_SYMTABS,
ALL_PSYMTABS, and ALL_MSYMBOLS macros.
* symmisc.c (dump_symtab, dump_psymtab, dump_msymbols,
dump_objfile):  Remove dummy args and results.  Move filename
comparisons to callers.
(printsyms_command, printpsyms_command, printmsyms_command,
printobjfiles_command):  iterate_over_* => ALL_*.  Compare filenames.
* symtab.c (lookup_symtab_1, lookup_symtab, lookup_partial_symtab,
lookup_symbol, find_main_psymtab, find_pc_symtab, sources_info,
list_symbols, make_symbol_completion_list):  Replace explicit
iteration with ALL_SYMTABS, ALL_PSYMTABS, or ALL_MSYMBOLS.
Eliminate Dijkstra flag crap, break out of loops with gotos.
(lookup_symtab_1):  Protect '/' tests from short filenames.
(cplus_mangled_symbol):  Move inline into lookup_symbol.
* xcoffexec.c (relocate_objfile_msymbols):  Remove poor hack.
(relocate_minimal_symbol):  Move inline to vmap_symtab.
(vmap_symtab):  Replace iteration with ALL_OBJFILES,
iterate_over_msymbols with ALL_MSYMBOLS.

Misc cleanup prior to release.

* dwarfread.c (dwarf_build_psymtabs):  Remove mainline test.
* mipsread.c (compare_symtabs, compare_psymtabs):  Remove, unused.
* mipsread.c:  Add prototypes for all static functions.

* symmisc.c (dump_symtab_lines, dump_symtabs, dump_last_symtab,
dump_blockvector, dump_block, dump_addrchass, dump_namespace,
dump_symbol, dump_type, dump_linetable, dump_strtbl):  Remove, unused.
* xcoffread.c (dump_symtab_lines, dump_symtabs, dump_last_symtab,
dump_blockvector, dump_block, dump_addrchass, dump_namespace,
dump_symbol, dump_type, dump_linetable, dump_strtbl):  Remove 2nd
unused copy!

* buildsym.c (define_symbol):  Handle global register variables
(from Pierre Willard).  Complain if register numbers are too large.