[Driver] Add -static-openmp driver option

Summary:
For Gnu, FreeBSD and NetBSD, this option forces linking with the static
OpenMP host runtime (similar to -static-libgcc and -static-libstdcxx).

Android's NDK will start the shared OpenMP runtime in addition to the static
libomp.  In this scenario, the linker will prefer to use the shared library by
default.  Add this option to enable linking with the static libomp.

Reviewers: Hahnfeld, danalbert, srhines, joerg, jdoerfert

Subscribers: guansong, cfe-commits

Tags: #clang

Fixes https://github.com/android-ndk/ndk/issues/1028

Differential Revision: https://reviews.llvm.org/D67200

llvm-svn: 371437