There's a merged pull request on the void-packages repository

tcl: don't build unnecessary compatibility functions.
https://github.com/void-linux/void-packages/pull/27708

Description:
./configure-time tests are incorrectly flagging some libc functions as
broken when cross-compiling.  Hard-code correct results of tests.
Without this patch, it seems that I cannot link some things (tclx)
against tcl on aarch64.