Remove /^\s*\*+\s*\$FreeBSD\$.*$\n/

Similar commit in main:
(cherry picked from commit 42b388439bd3)

NetBSD and OpenBSD have libc wrapper functions for the ARM_SYNC_ICACHE and
ARM_DRAIN_WRITEBUF sysarch operations. This change adds compatible functions
to our library. This should make it easier for various upstream sources to
support *BSD operating systems with a single variation of cache maintence
code in tools like interpreters and JIT compilers.

I consider the argument types passed to arm_sync_icache() to be especially
unfortunate, but this is intended to match the other BSDs.

Differential Revision:	https://reviews.freebsd.org/D20906

No references to any of these exist in the tree. The list was also
erratic with different architectures exporting different things
(arm64 and riscv exported none).

Reviewed by:	kib
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D18425

Previously, libc.so would initialize its notion of the break address
using _end, a special symbol emitted by the static linker following
the bss section.  Compatibility issues between lld and ld.bfd could
cause the wrong definition of _end (libc.so's definition rather than
that of the executable) to be used, breaking the brk()/sbrk()
interface.

Avoid this problem and future interoperability issues by simply not
relying on _end.  Instead, modify the break() system call to return
the kernel's view of the current break address, and have libc
initialize its state using an extra syscall upon the first use of the
interface.  As a side effect, this appears to fix brk()/sbrk() usage
in executables run with rtld direct exec, since the kernel and libc.so
no longer maintain separate views of the process' break address.

PR:		228574
Reviewed by:	kib (previous version)
MFC after:	2 months
Differential Revision:	https://reviews.freebsd.org/D15663

The arm, mips, and riscv MD Symbol.map files listed some (but not all)
of the softfloat symbols that were actually defined in softfloat.c.

While here, also remove entries for __fixuns[sd]fsi which are provided
by libcompiler_rt and not by libc.

Sponsored by:	DARPA / AFRL

i386 stopped exporting .cerror in r240152, and likewise for amd64 in
r240178. It is not used by other libraries on any platform, so apply
the same change to the remaining architectures.

Reviewed by:	jhibbits, jilles
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D5774

They are not used anywhere else in the base system and are an internal
implementation detail that does not need to be exposed.

Reviewed by:	kib
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D5728

handling.  For statically linked apps this uses the __exidx_start/end
symbols set up by the linker.  For dynamically linked apps it finds the
shared object that contains the given address and returns the location and
size of the exidx section in that shared object.

The dl_unwind_find_exidx() name is used by other BSD projects and Android,
and is mentioned in clang 3.5 comments as "the BSD interface" for finding
exidx data.  GCC (in libgcc_s) expects the exact same API and functionality
to be provided by a function named __gnu_Unwind_Find_exidx(), so we provide
that with an alias ("strong reference").

Reviewed by:	kib@
MFC after:	1 week

system libraries, for example libm.