bfd: make _bfd_section_size_insane part of the public API

bfd: make _bfd_section_size_insane part of the public API

If a BFD user is making use of a function like
bfd_get_section_contents to read a section into a pre-allocated
buffer, then that BFD user might also want to make use of
_bfd_section_size_insane prior to allocating the buffer they intend to
use in order to validate that the buffer size that plan to allocate is
sane.

This commit makes _bfd_section_size_insane public, by renaming it to
bfd_section_size_insane.

I've updated the existing uses within bfd/, I don't believe this
function is used outside of bfd/ currently.

One place that I plan to make use of this function is in
gdb/gdb_bfd.c, in the function gdb_bfd_get_full_section_contents.
This change isn't included in this commit, but will come later if/when
this has been merged into bfd.

There should be no change in behaviour after this commit.

bfd/

	* bfd-in2.h (bfd_section_size_insane): Add declaration.
	* compress.c (bfd_get_full_section_contents): Update for new name
	of _bfd_section_size_insane.
	(bfd_init_section_compress_status): Likewise.
	* dwarf2.c (read_section): Likewise.
	(_bfd_dwarf2_slurp_debug_info): Likewise.
	* libbfd.h (_bfd_section_size_insane): Remove declaration.
	* section.c (_bfd_section_size_insane): Rename to ...
	(bfd_section_size_insane): ... this.

binutils/

	* readelf.c (uncompress_section_contents): Update comment to
	account for new name of _bfd_section_size_insane.