[erlang-bugs] (unconditional) rebuild caused by gen_git_version

[Tuncer Ayaz]

Since R16 it's not possible anymore to quickly run make in a
previously built and otherwise unmodified tree.

$ make
# everything built
# run make again
$ make
...
 GEN    x86_64-unknown-linux-gnu/gen_git_version.mk
 CC     obj/x86_64-unknown-linux-gnu/opt/plain/erl_bif_info.o
..
 LD     /tmp/otp/master/bin/x86_64-unknown-linux-gnu/beam

This doesn't take long, but recreating an object file and relinking
the vm every time doesn't seem right to me. AFAICT, it was introduced
to include the git revision of the tree the vm was built from.

I don't have time to look into this right now, so no patch from me.