WITH_CLANG_BOOTSTRAP= for TARGET_ARCH=powerpc64 but bound to devel/powerpc64-binutils : can such be done?

[Mark Millard]

Currently head has switched to clang 3.9.0 but my
TARGET_ARCH=powerpc64for clang experiments for buildworld are blocked
by WITH_BINUTILS_BOOTSTRAP= 's ld stopping the buildworld via failing
asserts.

What I'd like to do is build the bootstrap clang but bound to a
devel/powerpc64-binutils vintage to see if that works. So binutils
being "cross tool chain" (even when directly invoked by clang) but
clang itself not being cross tool chain but bootstrapped?

(elftoolchain may need to be considered with binutils.)

Do you know if there is a way for me to make assignments in a
SRC_ENV_CONF file that might enable such a combination? Or
do I need to modify the build environment to be non-standard?

So far in my reading /usr/src/Makefile.inc1 I've not seen any
combination of settings that look like it would go through and
work for what I've described here.

===
Mark Millard
markmi at dsl-only.net