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

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

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

Approved by: re (implicit)

Compile libgcov without stack protection. It can be linked into
both static and dynamic binaries compiled with or without stack
protection and should not depend on libssp_nonshared.a symbols.

Discussed with: kib
PR: bin/139052

Compile static gcov library with -fPIC to match what stock GCC builds
are doing. This is required for libgcov.a to be usable on amd64.

Reported by: stas

Update bmake glue to build GCC 4.2.

Also:
Switch FreeBSD to use libgcc_s.so.1.

Use dl_iterate_phdr to locate shared objects' exception frame
info instead of depending on older register_frame_info machinery.
This allows us to avoid depending on libgcc_s.so.1 in binaries
that do not use exception handling directly. As an additional
benefit it breaks circular libc <=> libgcc_s.so.1 dependency too.

Build newly added libgomp.so.1 library, the runtime support
bits for OpenMP.

Build LGPLed libssp library. Our libc provides our own
BSD-licensed SSP callbacks implementation, so this library
is only built to benefit applications that have hadcoded
knowledge of libssp.so and libssp_nonshared.a. When linked
in from command line, these libraries override libc
implementation.

Convert NO_PROFILE and NO_LIB32 to new style.

NODOCCOMPRESS -> NO_DOCCOMPRESS
NOINFO -> NO_INFO
NOINFOCOMPRESS -> NO_INFOCOMPRESS
NOLINT -> NO_LINT
NOPIC -> NO_PIC
NOPROFILE -> NO_PROFILE

For variables that are only checked with defined(), don't provide
any fake value.

Add libgcov, a runtime support library for binaries compiled for basic
block profiling.