Some code are spent for nest case since the build system
does not support subdir Makefile. It would be nice if
qemu can change the build system like kernel's build system one
day, then we can avoid these troubles.
The code looks fine.
Reviewed-by: Wenchao Xia
Adds extract-libs in LINK to expand any "per object libs", the syntax to define
such a libs options is like:
foo.o-libs := $(CURL_LIBS)
in block/Makefile.objs.
Similarly,
foo.o-cflags := $(FOO_CFLAGS)
is also supported.
"foo.o" must be listed a nested var (e.g. common-obj-y) t
