Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC: r231616, r232497, r234337

Add __aeabi_read_tp function required for thread-local storage.

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Unbreak arm build by removing duplicate symbols.

Some libc symbol map cleanups.

net: endhostdnsent is named _endhostdnsent and is
private to netdb family of functions.

posix1e: acl_size.c has been never compiled in,
so there's no "acl_size".

rpc: "getnetid" is a static function.

stdtime: "gtime" is #ifdef'ed out in the source.

some symbols are specific only to some architectures,
e.g., ___tls_get_addr is only defined on i386.

__htonl, __htons, __ntohl and __ntohs are no longer
functions, they are now (internal) defines in
<machine/endian.h>.

Submitted by: ru

Use __mcount() instead of _mcount() to reduce diffs with NetBSD.

Do not export 'end' symbol. It is not meant to be visible to outside
world and it wreak havoc if libc collides with other versioned
libraries.

Remove .mcount from gmon's Symbol map and add it to the appropriate
arch. It can be named differently depending on the arch (.mcount,
_mcount).

Submitted by: marius

Use C comments since we now preprocess these files with CPP.

Add symbol maps and initial symbol version definitions to libc.

Reviewed by: davidxu