Do not pass archive files containing non-native object files.

The MSVC linker doesn't like archive files containing non-native object
files.

When we are doing an LTO build, we may create archive files containing
both LLVM bitcode files and native object files. For example, if a
project contains assembly files and C++ files, we create native object
files for the assembly files and LLVM bitcode files for the C++ files.

With the /msvclto option, LLD passes archive files to the MSVC linker.
Previously, we didn't pass archive files if they contain at least one
bitcode files. That wasn't correct because the native object files that
weren't passed to the MSVC linker may be needed to complete linking.

In this patch, we create new temporary archive files to strip bitcode
files.

Differential Revision: https://reviews.llvm.org/D31053

llvm-svn: 297997