...as needed e.g. for <https://bugs.llvm.org/show_bug.cgi?id=32349> "r294897 +
NewGVN cause build failure with LibreOffice", by applying
<http://git.savannah.gnu.org/cgit/libtool.git/commit/
?id=d9a35fe9d3508b5c0d56e7f2ec80fc05e8415fa3> "libtool: Discard '-mllvm $arg'
options when linking."

Change-Id: Id2afc3c8af3c6c9595e7cb33cef5084a74f78cb0