Replace bsearch with a std::lower_bound-based search

Replace bsearch with a std::lower_bound-based search

This is more type-safe and can be faster due to inlining and
avoiding overhead from calling through a function pointer.

gdb/ChangeLog:

2019-10-29  Christian Biesinger  <cbiesinger@google.com>

	* Makefile.in (HFILES_NO_SRCDIR): Add gdb_binary_search.h.
	* dwarf2-frame.c (bsearch_fde_cmp): Update.
	(dwarf2_frame_find_fde): Replace bsearch with gdb::binary_search.
	* gdbsupport/gdb_binary_search.h: New file.

Change-Id: I07e0a0e333f4062b27fc68d3a3f24881ebc68fd4