The toolchain variables were overwritten anyway in
`makefiles/toolchain/gnu|llvm.inc.mk` as they use `=` affectation,
except for `OBJCOPY`.
On my Linux ubuntu bionic machine, the only difference for `info-build`
with both gnu/llvm and also with LTO=1
is that it now uses an absolute path for `objcopy`
-OBJCOPY: objcopy
+OBJCOPY: /usr/bin/objcopy
On the OSX 17.7.0 I tested, there was no difference.
9c5688ea27