Initial fixes for linux x32
Tested with a local build of rustc. The main test can be compiled but fails to execute (receives SIGTRAP, which I think in this case indicates memory violation, I will open an issue in the rustc repo).
This PR is important because it fixes the definition of `c_long` and `c_ulong`. Without these fixes, rustc crash with the error:
```
Cannot emit physreg copy instruction
UNREACHABLE executed at /checkout/src/llvm/lib/Target/X86/X86InstrInfo.cpp:5778!
```
Related https://github.com/rust-lang/rust/issues/37976
Rebase of #610 and also move emscripten up much higher in the hierarchy to
ensure that it doesn't have too much of a ripple effect on other platforms.
This involved moving down a good number of definitions, but hopefully was done
with care to not break anything!
We now create an additional binary `linux_fcntl` for testing this
since there are header conflicts when including all necessary headers.
This binary is run on all platforms even though it's empty on all non-
Android/non-Linux platforms.
Testing has been switched from a custom binary to using a runner-less
test (or pair of tests). This means that for local development a simple
`cd libc-test && cargo test` will run all the tests. CI has also been
updated here to reflect that.
It's now broken due to changes in the `gcc` crate and having a too-old compiler,
and in general it's unfortunately architecturally so different from the other
test frameworks that it's difficult to maintain over time.
Add KERN_USERMOUNT and KERN_ARND to don't check list on OpenBSD
These [two constants are no longer in OpenBSD](3f376b0849/sys/sys/sysctl.h (L133-L140)). They were preventing the the tests from passing. With this change the test now pass:
```
CC=egcc cargo run
Compiling libc v0.2.29 (file:///home/vagrant/libc)
Compiling libc-test v0.1.0 (file:///home/vagrant/libc/libc-test)
Finished debug [unoptimized + debuginfo] target(s) in 11.7 secs
Running `/home/vagrant/libc/target/debug/libc-test`
RUNNING ALL TESTS
PASSED 5935 tests
```
They are still present in bitrig so I moved them there.
It needs to be skipped during testing because there's no way to include
a combination of headers that will expose it without giving a "type has
already been defined" error.
Adding missing structs from linux/user.h
Adding structs from linux/user.h (or sys/user.h depending on OS version). This adds the linux user_regs_struct and user struct from sys/user.h into libc for x86 and x86_64. Also, bumping the version number.
As an aside, I was wondering if this was also the right place to add the bit offsets for the [EFLAGS register ](https://en.wikibooks.org/wiki/X86_Assembly/X86_Architecture#EFLAGS_Register)? These aren't defined anywhere in the linux system libraries instead the definition seems to just be in the x86 and x86_64 documentation but they are useful for anyone looking to interpret eflags. If libc is the right place for these constants I'd like the opportunity to add them before it's merged in. :)
