This was a bit trickier than it should be due to symbol conflicts with
zig's compiler-rt implementation. We attempt to use weak linkage in
our compiler-rt, but this does not seem to be working in all cases. I
manually disabled export of the problematic compiler-rt math functions
in order to cross compile musl's libc.so for all targets as input to
`tools/gen_stubs.zig`.
Other than that, this update went fairly smoothly. Quite a few
additional symbols were added to the blacklist in `tools/gen_stubs.zig`
due to recent reorganization of zig's compiler-rt.
This is the result of the work on tools/gen_stubs.zig. It now uses the
preprocessor to emit different symbols and sizes depending on the
architecture. The data is collected directly from multiple libc.so files
on disk built with upstream musl.
Closes#8178
Addresses #8896 for musl
There is still room for further improvement to this, which is to
put `.ds` directives after symbols that are not followed by aliases, to
avoid the potential problem of a linker believing that all symbols are
aliases of each other.
