i686-pc-windows-msvc also has target_thread_local now

Author: RalfJung

ci-test.sh

@@ -55,7 +55,6 @@ std)
 
     # A 64bit little-endian and a 32bit big-endian target,
     # as well as targets covering all major OSes and both ABIs on Windows.
-    # i686-pc-windows-msvc is special as it does not have `cfg(target_thread_local)`.
     for TARGET in x86_64-unknown-linux-gnu mips-unknown-linux-gnu aarch64-apple-darwin i686-pc-windows-msvc x86_64-pc-windows-gnu; do
         echo "::group::Testing std ($TARGET)"
         MIRIFLAGS="$DEFAULTFLAGS -Zmiri-disable-isolation" \