Remove all invocations of SetSubDirSupportedPlatformsBeOSCompatible.

Removal of non-Haiku target platform logic from build system (part 1.)

Following recent changes to use libroot_build on Haiku also, it is now
actually impossible to build Haiku components on non-Haiku platforms
(BeOS R5, Dan0, BONE, Zeta), so we can remove any logic related to this.

This is only the first part; still to be removed are:
* SetSubDirSupportedPlatformsBeOSCompatible
* HOST_PLATFORM_BEOS_COMPATIBLE
* TARGET_PLATFORM_BEOS_COMPATIBLE

bin/mail: move to 'mail_utils' subdir.

Use libstdc++, libsupc++ and libgcc from gcc_syslibs.

* Instead of faking libstdc++.so from libstdc++.a, use libstdc++.so
from the gcc_syslibs build feature for everything except x86_gcc2.
* Use libgcc_s.so from the gcc_syslibs build feature for everything but
x86_gcc2 (which still carries libgcc as part of libroot.so).
* Drop filtering of libgcc objects for libroot, as that is no longer
necessary since we're only using libgcc-as-single-object for libroot
with x86_gcc2, where the filtered object file doesn't exist. Should
the objects that used to be filtered cause any problems as part of
libgcc_s.so, we can always filter them as part of the gcc build.
* Use libsupc++.so from the gcc_syslibs build feature for everything but
x86_gcc2.
* Adjust all Jamfiles accordingly.
* Deactivate building of faked libstdc++.so for non-x86-gcc2. For
x86_gcc2, we still build libstdc++.so from the sources in the Haiku
source tree as part of the Haiku build .
* Put gcc_syslibs package onto the image, when needed.

Remove the old "CVS" package rules

... and all their invocations.

Renaming mail-mbox utilities as per humdingers request in #4582.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33194 a95241bf-73f2-0310-859d-f6bbb57e9c96

Use libstdc++, libsupc++ and libgcc from gcc_syslibs.

* Instead of faking libstdc++.so from libstdc++.a, use libstdc++.so
from the gcc_syslibs build feature for everything except x86_gcc2.
* Use libgcc_s.so from the gcc_syslibs build feature for everything but
x86_gcc2 (which still carries libgcc as part of libroot.so).
* Drop filtering of libgcc objects for libroot, as that is no longer
necessary since we're only using libgcc-as-single-object for libroot
with x86_gcc2, where the filtered object file doesn't exist. Should
the objects that used to be filtered cause any problems as part of
libgcc_s.so, we can always filter them as part of the gcc build.
* Use libsupc++.so from the gcc_syslibs build feature for everything but
x86_gcc2.
* Adjust all Jamfiles accordingly.
* Deactivate building of faked libstdc++.so for non-x86-gcc2. For
x86_gcc2, we still build libstdc++.so from the sources in the Haiku
source tree as part of the Haiku build .
* Put gcc_syslibs package onto the image, when needed.

Remove the old "CVS" package rules

... and all their invocations.

Renaming mail-mbox utilities as per humdingers request in #4582.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33194 a95241bf-73f2-0310-859d-f6bbb57e9c96