[LLVMdev] make fails to detect changes in case srcdir != objdir

[Gregory Petrosyan]

LLVM makefiles can't detect source changes in case objdir != srcdir, e.g. I've
managed to get my pass listed in 'opt -help' only after removing opt subdir
from objdir and running make again. Re-configuring LLVM also does not trigger
rebuild when running make, e.g. after initial 'configure --enable-targets=x86'
I've managed to get C backend only after removing objdir and re-configuring
(was too lazy to check if 'make clean' is sufficient).

Does anyone know what can be a source for these problems?

	Gregory