Revert "stage2: fix compilation of self-hosted compiler with -Denable-llvm"
This broke compiling with -Dstage1 on Windows, because it added the
cpp_source_files to the compilation multiple times.
This reverts commit c81ae52ee0b2e952f8ed9c5c6517af8182bb09c1.
79a5151155Andrew Kelley committed on 12/29/2020, 6:41:29 AMparent8ab870c