_tls_index vs tls_index for x86-windows

[jedisct1]

Zig Version

0.11.0-dev.175+7eed028f

Steps to Reproduce and Observed Behavior

git clone --depth=1 https://github.com/jedisct1/libsodium.git
cd libsodium
zig build -Dtarget=x86-windows

LLD Link... lld-link: error: <root>: undefined symbol: _tls_index
error: FileNotFound

The _tls_index symbol is properly found when building for the x86_64-windows and aarch64-windows targets, not for x86-windows.

x86-windows expects _tls_index to be tls_index in lib/zig/libc/mingw/crt/tlssup.c.

Expected Behavior

Being able to build shared libraries for x86-windows.