glibc: Define _IO_stdin_used in start code and reference it in stub asm.
This is necessary to inform the real, non-stub glibc that a program built with
Zig is using a modern `FILE` structure, i.e. glibc 2.1+. This is particularly
important on lesser-used architectures where the legacy code is poorly tested;
for example, glibc 2.40 introduced a regression for the legacy case in the
libio cleanup code, causing all Zig-compiled MIPS binaries to crash on exit.
5dd2bb525dAlex Rønne Petersen committed on 8/23/2024, 6:09:20 PM· committed by Andrew Kelleyparentdf6907f