Subzero makefile changes for linking a static llvm2ice nexe w/ LLVM build sys.

Subzero makefile changes for linking a static llvm2ice nexe w/ LLVM build sys.

Need to list more dependencies, otherwise the static
link fails. The current unsandboxed build is a shared build
which uses libLLVM-3.*.so.

Also mess with the CXXFlags a bit. The current pnacl-llc
nexe build uses O3, but that triggers a method pointer bug:
https://code.google.com/p/nativeclient/issues/detail?id=3857,
so override that with O2. We may just want to change the
pnacl-llc build as well (maybe use Os), but I don't
know of the performance implications right now.

Use gnu++11, because of newlib + libc++.

Toggle the feature flags to be a MINIMAL build when
building the sandboxed translator w/ the LLVM-based
Makefile.

Goes with build script change https://codereview.chromium.org/945473003/

BUG= https://code.google.com/p/nativeclient/issues/detail?id=4091
BUG= https://code.google.com/p/nativeclient/issues/detail?id=3857
R=dschuff@chromium.org, kschimpf@google.com

Committed: https://gerrit.chromium.org/gerrit/gitweb?p=native_client/pnacl-subzero.git;a=commit;h=e837e1a38b79ddf82f5497d80a4c2fe87241dff2

[jvoung (off chromium), 2015-02-19 23:10:35]

jvoung@chromium.org changed reviewers:
+ dschuff@chromium.org, kschimpf@google.com, stichnot@chromium.org

[Karl, 2015-02-19 23:15:34]

lgtm

[Derek Schuff, 2015-02-23 17:06:21]

lgtm

[jvoung (off chromium), 2015-03-02 22:22:02]

Committed patchset #3 (id:40001) manually as
e837e1a38b79ddf82f5497d80a4c2fe87241dff2 (tree was closed).