With `libunwind` and `libcxxabi` included in `libcosmo`, we can now
allow users to build C++ applications with exceptions and RTTI enabled.
The default is still disabling these two to avoid bloating the binary.
Closes#1065
The toolchain will now be downloaded going forward from multiple pinned
URLs which have shasums. Either wget or curl must be installed.
This change unblocks #1053
It's now possible to pass flags like -Xaarch64-march=armv8.2-a+dotprod
so that cosmocc will use newer ARM ISAs. For AMD64 there's another one
worth mentioning, which looks like this: -Xx86_64-mssse3
The `cosmocc` compiler is now being distributed as a self-contained
toolchain that's path-agnostic and it no longer requires you clone the
Cosmop repo to use it. The bin/ folder has been deleted from the mono
repo. The `fatcosmocc` command has been renamed to `cosmocc`. MacOS
support now works very well.