Replace some more qsort calls with std::sort

Replace some more qsort calls with std::sort

This has better typesafety, avoids a function pointer indirection,
and can benefit from inlining.

gdb/ChangeLog:

2019-10-19  Christian Biesinger  <cbiesinger@google.com>

	* bcache.c (bcache::print_statistics): Use std::sort instead of qsort.
	* breakpoint.c (bp_locations_compare): Rename to...
	(bp_location_is_less_than): ...this, and change to std::sort semantics.
	(update_global_location_list): Use std::sort instead of qsort.
	* buildsym.c (compare_line_numbers): Rename to...
	(lte_is_less_than): ...this, and change to std::sort semantics.
	(buildsym_compunit::end_symtab_with_blockvector): Use std::sort
	instead of qsort.
	* disasm.c (compare_lines): Rename to...
	(line_is_less_than): ...this, and change to std::sort semantics.
	(do_mixed_source_and_assembly_deprecated): Call std::sort instead
	of qsort.
	* dwarf2-frame.c (qsort_fde_cmp): Rename to...
	(fde_is_less_than): ...this, and change to std::sort semantics.
	(dwarf2_build_frame_info): Call std::sort instead of qsort.
	* mdebugread.c (compare_blocks):
	(block_is_less_than): ...this, and change to std::sort semantics.
	(sort_blocks): Call std::sort instead of qsort.
	* objfiles.c (qsort_cmp): Rename to...
	(sort_cmp): ...this, and change to std::sort semantics.
	(update_section_map): Call std::sort instead of qsort.
	* remote.c (compare_pnums): Remove.
	(map_regcache_remote_table): Call std::sort instead of qsort.
	* utils.c (compare_positive_ints): Remove.
	* utils.h (compare_positive_ints): Remove.
	* xcoffread.c (compare_lte): Remove.
	(arrange_linetable): Call std::sort instead of qsort.

Change-Id: Ibcddce12a3d07448701e731b7150fa23611d86de