* bcache.c, bcache.h: New files to implement a byte cache.

	* bcache.c, bcache.h: New files to implement a byte cache.
	* Makefile.in (SFILES): Add bcache.c.
	(symtab_h): Add bcache.h.
	(HFILES_NO_SRCDIR): add bcache.h
	(COMMON_OBJS): Add bcache.o
	(bcache.o): New target.
	* dbxread.c (start_psymtab): Make global_syms & static_syms
 	type "partial_symbol **".
	* hpread.c (hpread_start_symtab):  Ditto.
	* os9kread.c (os9k_start_psymtab):  Ditto.
	* stabsread.h (start_psymtab):  Ditto.
	* {symfile.c, symfile.h} (start_psymtab_common):  Ditto.
	* maint.c (maintenance_print_statistics): Call
 	print_symbol_bcache_statistics.
	* objfiles.c (allocate_objfile): Initialize psymbol bcache malloc
	and free pointers.
	* solib.c (allocate_rt_common_objfile): Ditto.
	* symfile.c (reread_symbols):  Ditto.
	(free_objfile): Free psymbol bcache when objfile is freed.
	(objfile_relocate): Use new indirect psymbol pointers.
	* objfiles.h (struct objfile): Add psymbol cache.
	* symfile.c (compare_psymbols): Now passed pointers to pointers to
	psymbols.
	(reread_symbols): Free psymbol bcache when freeing other objfile
	resources.
	(add_psymbol_to_list, add_psymbol_addr_to_list): Initialize new
	psymbol using the psymbol bcache.
	(init_psymbol_list): Psymbol lists now contain pointers rather than
	the actual psymbols.
	* symfile.h (psymbol_allocation_list): Psymbol lists now dynamically
	grown arrays of pointers.
	(ADD_PSYMBOL_VT_TO_LIST): Initialize new symbol using the psymbol
	bcache.
	* symmisc.c (print_partial_symbols): Now takes pointer to pointer
	to partial symbol.
	(print_symbol_bcache_statistics): New function to print per objfile
 	bcache statistics.
	(print_partial_symbol, print_partial_symbols,
 	maintenance_check_symtabs, extend_psymbol_list):
 	Account for change to pointer to pointer to partial symbol.
	* symtab.c (find_pc_psymbol, lookup_partial_symbol, decode_line_2,
	make_symbol_completion_list):
 	Account for change to pointer to pointer to partial symbol.
	* symtab.h (bcache.h): Include.
	* xcoffread.c (xcoff_start_psymtab): Make global_syms & static_syms
 	type "partial_symbol **".