MFC r339738, r339744, r339770, r339773, r339864-r339866, r339907-r339908, r339912...

MFC r339738, r339744, r339770, r339773, r339864-r339866, r339907-r339908, r339912-r339913, r339916, r339954, r340213, r340395, r340840, r340910-r340911, r341424, r342773, r342974, r351027, r352073:

MFC the BSD crtbegin to stable/12 but keep it disabled.

r339738:
Implement a BSD licensed crtbegin/crtend

These are needed for .ctors/.dtors and .jcr handling. The former needs
all the function pointers to be called in the correct order from the
.init/.fini section. The latter just needs to call a gcj specific function
if it exists with a pointer to the start of the .jcr section.

This is currently disabled until __dso_handle support is added.

Reviewed by:	emaste
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D17587

r339744:
Add a missing include for src.opts.mk. Without it MK_TESTS isn't defined.

MFC with:	r339738
Sponsored by:	DARPA, AFRL

r339770:
Drop the csu tests WARNS to 5 to fix the powerpc64 build.

MFC with:	r339738
Sponsored by:	DARPA, AFRL

r339773:
Add __dso_handle to the BSD crtbegin. This is used to identify shared
objects.

MFC with:	r339738
Sponsored by:	DARPA, AFRL

r339864:
Check __dso_handle is NULL in non-DSO objects. It should only be non-NULL
when accessed from a shared object.

MFC with:	r339738
Sponsored by:	DARPA, AFRL

r339865:
Include the csu test directories in BSD.tests.dist

MFC with:	r339738
Sponsored by:	DARPA, AFRL

r339866:
Make the .ctors, .dtors, and .jcr markers as static. They shouldn't be
accessible from out of the files they are defined in.

MFC with:	r339738
Sponsored by:	DARPA, AFRL

r339907:
The jcr argument to _Jv_RegisterClasses is used, stop marking it otherwise.

MFC with:	r339738
Sponsored by:	DARPA, AFRL

r339908:
Run the csu tests on a DSO. This builds the tests into a shared library,
then runs these from the base test programs. With this we can check
crtbeginS.o and crtendS.o are working as expected.

MFC with:	r339738
Sponsored by:	DARPA, AFRL

r339912:
Fix the location of the static keyword.

MFC with:	r339738
Sponsored by:	DARPA, AFRL

r339913:
Disable the .preinit_array test in DSOs, ld.bfd fails to link objects with
the section.

MFC with:	r339738
Sponsored by:	DARPA, AFRL

r339916:
Build the csu tests on all architectures.

The tests haven't been run them, but this is enough to build them so I can
get feedback on if the various crt.h headers are correct.

MFC with:	r339738
Sponsored by:	DARPA, AFRL

r339954:
Add __used to __CTOR_LIST__ and __DTOR_LIST__

Enabling BSD_CRTBEGIN on amd64 resulted in
error: unused variable '__CTOR_LIST__'.

__CTOR_LIST__ is indeed unused in crtbegin.c; it marks the beginning of
the .ctors array and is used in crtend.c.  Annotate __DTOR_LIST__ as
well for consistency.

Discussed with:	andrew
MFC with:	r339738
Sponsored by:	The FreeBSD Foundation

r340213:
Add the (untested) mips and sparc64 .init call sequences.

The BSD crtbegin/crtend code now builds on all architectures, however
further work is needed to check if it works correctly.

MFC with:	r339738
Sponsored by:	DARPA, AFRL

r340395:
Run __cxa_finalize in shared objects in the destructor path.

When we have .dtors call them before .dtor handling, otherwise call from
a destructor.

PR:		233056
MFC with:	r339738
Sponsored by:	DARPA, AFRL

r340840:
Mark the function called by the MIPS .init/.fini sequence with .local.

As with r328939 we need to mark local symbols as such. Without this the
assembly parser treats the symbols as global and created relocations
against these private symbols.

MFC with:	r339738
Sponsored by:	DARPA, AFRL

r340910:
Add the missing 0 at the end of the .jcr section.

Without this the dynamic library test was failing as it was calling
_Jv_RegisterClasses multiple times.

r340911:
Re-enable the dynamiclib tests. These should be fixed by r340910.

r341424:
Disable the BSD CRT code on powerpc and sparc64, they need extra crt*.o
files that haven't been implemented.

Reported by:	sbruno
MFC with:	r339738
Sponsored by:	DARPA, AFRL

r342773:
Add explicit csu test dependency

lib/csu/tests/dynamiclib requires libh_csu.so be built first.  I'm not
sure this is the most correct/best way to address this but it solves
the issue in my testing.

PR:		233734
Sponsored by:	The FreeBSD Foundation

r342974:
Create crtsavres.o for powerpc builds

Summary:
GCC expects to link in a crtsavres.o on powerpc platforms.  On
powerpc64 this is an empty file, but on powerpc and powerpcspe this does contain
some save/restore functions, which may not actually be necessary for newer
modern GCC and clang.  This appeases the in-tree gcc, though, and is needed in
order to switch to the BSD CRTRBEGIN.

PR:	233751
Reviewed By: andrew
Differential Revision: https://reviews.freebsd.org/D18826

r351027:
Enable BSD_CRTBEGIN on powerpc

In r342974 jhibbits added support to build crtsavres.o. This was the
blocker for BSD_CRTBEGIN to be enabled there. As such enable this
option again.

Reviewed by:	jhibbits
Sponsored by:	DARPA, AFRL

r352073:
csu: Add the riscv .init call sequence

Reviewed by:	br
Sponsored by:	Axiado
Differential Revision:	https://reviews.freebsd.org/D21537