Summary:
Add a new option (/llvmlibempty). If passed and llvm-lib does not give an error, it will create a valid output archive even if empty.
By default, llvm-lib mimicks lib.exe: if given no input files, it doesn't create its output file at all. This is incompatible with some build systems, so we add a command-line option to toggle this compatibility behavior.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D78894
Similarly to SVN r317189 for llvm-dlltool, these are probably
easier to find in a tools subdirectory with a name identical to
the tool, than in a toplevel directory with a different name.
This matches the move of LibDriver itself in SVN r302995.
Differential Revision: https://reviews.llvm.org/D39531
llvm-svn: 317262