`@cImport` breakage on `loongarch64-linux` after #24497

[alexrp]

ref ziglang/zig#24497

test
└─ test-standalone
   └─ standalone_test_cases
      └─ standalone_test_cases.glibc_compat
         └─ run exe native-linux-gnu.2.38
            └─ compile exe native-linux-gnu.2.38 Debug native-linux-gnu.2.38 failure
error: /home/ci/zig/lib/libc/include/generic-glibc/stdio.h:376:28: error: 'void' must be the first parameter if specified
                     __gnuc_va_list __arg) __nonnull ((1));
                           ^
/home/ci/zig/lib/libc/include/generic-glibc/stdio.h:381:74: error: 'void' must be the first parameter if specified
extern int vprintf (const char *__restrict __format, __gnuc_va_list __arg);
                                                                         ^
/home/ci/zig/lib/libc/include/generic-glibc/stdio.h:384:28: error: 'void' must be the first parameter if specified
                     __gnuc_va_list __arg) __THROWNL;
                           ^
/home/ci/zig/lib/libc/include/generic-glibc/stdio.h:393:62: error: 'void' must be the first parameter if specified
                      const char *__restrict __format, __gnuc_va_list __arg)
                                                             ^
/home/ci/zig/lib/libc/include/generic-glibc/stdio.h:401:29: error: 'void' must be the first parameter if specified
                      __gnuc_va_list __arg)
                            ^
/home/ci/zig/lib/libc/include/generic-glibc/stdio.h:414:28: error: 'void' must be the first parameter if specified
                     __gnuc_va_list __arg)
                           ^
/home/ci/zig/lib/libc/include/generic-glibc/stdio.h:494:27: error: 'void' must be the first parameter if specified
                    __gnuc_va_list __arg)
                          ^
/home/ci/zig/lib/libc/include/generic-glibc/stdio.h:501:73: error: 'void' must be the first parameter if specified
extern int vscanf (const char *__restrict __format, __gnuc_va_list __arg)
                                                                        ^
/home/ci/zig/lib/libc/include/generic-glibc/stdio.h:506:60: error: 'void' must be the first parameter if specified
                    const char *__restrict __format, __gnuc_va_list __arg)
                                                           ^
/home/ci/zig/lib/libc/include/generic-glibc/stdio.h:543:12: error: 'void' must be the first parameter if specified
extern int __REDIRECT (vfscanf,
           ^
/home/ci/zig/lib/libc/include/generic-glibc/sys/cdefs.h:410:46: note: expanded from here
# define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
                                             ^
/home/ci/zig/lib/libc/include/generic-glibc/stdio.h:545:57: note: expanded from here
                        const char *__restrict __format, __gnuc_va_list __arg),
                                                        ^
/home/ci/zig/lib/libc/include/generic-glibc/stdio.h:548:12: error: 'void' must be the first parameter if specified
extern int __REDIRECT (vscanf, (const char *__restrict __format,
           ^
/home/ci/zig/lib/libc/include/generic-glibc/sys/cdefs.h:410:46: note: expanded from here
# define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
                                             ^
/home/ci/zig/lib/libc/include/generic-glibc/stdio.h:549:25: note: expanded from here
                                __gnuc_va_list __arg), __isoc99_vscanf)
                        ^
/home/ci/zig/lib/libc/include/generic-glibc/stdio.h:551:12: error: 'void' must be the first parameter if specified
extern int __REDIRECT_NTH (vsscanf,
           ^
/home/ci/zig/lib/libc/include/generic-glibc/sys/cdefs.h:418:11: note: expanded from here
     name proto __asm__ (__ASMNAME (#alias)) __THROW
          ^
/home/ci/zig/lib/libc/include/generic-glibc/stdio.h:554:28: note: expanded from here
                            __gnuc_va_list __arg), __isoc99_vsscanf)
                           ^
error: the following build command failed with exit code 1:
/home/ci/zig/zig-global-cache/o/939a760368a29847ebad74633afba044/translate-c -x c -isystem /home/ci/zig/lib/compiler/aro/include -fno-PIE -fPIC -gdwarf-4 -gdwarf32 -fno-lto -MD -MV -MF /home/ci/zig/zig-local-cache/tmp/298c8c5274292789/cimport.h.d -fhosted -nostdinc -D__GLIBC_MINOR__=38 -isystem /home/ci/zig/lib/include -isystem /home/ci/zig/lib/libc/include/loongarch-linux-gnu -isystem /home/ci/zig/lib/libc/include/generic-glibc -isystem /home/ci/zig/lib/libc/include/loongarch-linux-any -isystem /home/ci/zig/lib/libc/include/any-linux-any -O0 -target loongarch64-linux.5.19...6.16-gnu.2.38 -mcpu=la664-32bit+32s+64bit+d+div32+f+frecipe-la_global_with_abs-la_global_with_pcrel-la_local_with_abs+lam_bh+lamcas+lasx+lbt+ld_seq_sa+lsx+lvz-prefer_w_inst-relax+scq+ual -I /home/ci/deps/zig+llvm+lld+clang-loongarch64-linux-musl-0.16.0-dev.157+7fdd60df1/include /home/ci/zig/zig-local-cache/tmp/298c8c5274292789/cimport.h -o /home/ci/zig/zig-local-cache/tmp/298c8c5274292789/cimport.zig

cc @Vexu this looks like an Aro bug?

[alexrp]

I see what's wrong: Aro's logic for generating the valist type is out of sync with Zig's. I'll put up a PR to fix that shortly.