Support .a output files

[Akuli]

This makes it easy to sprinkle a little bit of Jou code into a project written in C. If you do -o foo.a when compiling Jou code, foo.a will contain object files for your program and whatever it uses from the Jou standard library.

For example, I placed this to test.jou:

import "stdlib/io.jou"
import "stdlib/list.jou"
import "stdlib/mem.jou"


def main() -> int:
    args = List[byte*]{}
    args.append("Hello")
    args.append(" ")
    args.append("World!")
    args.append("\n")

    for i = 0; i < args.len; i++:
        printf("%s", args.ptr[i])

    free(args.ptr)
    return 0

And compiled it to .a and gave that to a C compiler:

akuli@akuli-desktop:~/jou$ jou -o test.a test.jou
akuli@akuli-desktop:~/jou$ file test.a
test.a: current ar archive
akuli@akuli-desktop:~/jou$ cc test.a
akuli@akuli-desktop:~/jou$ ./a.out
Hello World!

Here's what ended up in the .a file:

akuli@akuli-desktop:~/jou$ ar t test.a
_assert_fail_6462dea0597d2c04_75f89d3cb3be1ebe.o
test_dce56ce79d1cbb8c_c159ba627f5e1510.o
io_113a41539cd5dd30_ad9ac958397bd736.o
list_665829f653098331_b202293f74d46422.o
mem_1d45d615c5de45c1_4e6b4fbee1296e6b.o

If the Jou code contains link statements, you will need to specify the corresponding flags when compiling the .a file with a C compiler:

akuli@akuli-desktop:~/jou$ jou -o compiler.a compiler/main.jou 
akuli@akuli-desktop:~/jou$ cc compiler.a -L/usr/lib/llvm-19/lib -lLLVM-19
akuli@akuli-desktop:~/jou$ ./a.out examples/hello.jou 
Hello World

Fixes #773

[Akuli]

• get CI green
• add tests
• add documentation