Self build with LTO on OS X

Should Clang be able to build itself with LTO/-O4?

Trying it with both 2.8 and 2.9 official releases fails at link time on OS X 10.6.7...

If this problem is the same as the general "LTO on OS X" problem, is this/will this be solvable at all? Or will Mac Clang users simply have to work with whatever Clang version (and accompanying system linker) Apple provides them with?

I install Clang (first built with Apple's llvm-gcc) into /usr/bin (thus overwriting the official one) which, I suppose, should be equivalent or 'better' than setting DYLD_LIBRARY_PATH (as recommended here and here but it still does not work.

Overriding clang without updating the LTO library used by the linker (/usr/lib/libLTO.dylib) is probably not a good idea, as the clang TOT may produce bitcode than an old library cannot read.

-- Jean-Daniel