Install copyright notices into the final package. This makes LLVM MinGW
comply with many of the licenses (which require attribution), and also
makes it easier for users of LLVM MinGW to audit licenses of software
they use.
For build-mingw-w64.sh to succeed when installing to such a path,
the mingw-w64 version has to be updated to the latest git master.
build-mingw-w64-libraries.sh still fails in this case, as libtool
fails to properly quote $LD in a test for whether the linker is GNU ld.
On some distributions, e.g. openSUSE, the libraries for 64 bit
architectures end up stored in <target>/<triplet>/lib64 instead of
plain "lib".
(This is caused by their use of a site script for configure, which
overrides libdir when the host triplet matches 64 bit architecture
names - even if it's a triple for cross compilation for a totally
different OS. This only affects the libraries and not mingw-w64-crt,
as the crt's makefiles manually set the output directory name.)
This fixes https://github.com/mstorsjo/llvm-mingw/issues/51.
Matthew "strager" Glazar