Merge from emacs-26

65889a6d12 Fix bootstrap infloop in GNU/Linux alpha
48efd1c98b Minor fix of a recent documentation change
3302b7cd7f Mention the NSM in the gnutls variable doc strings
40c2ce743b Remove test code from last commit
e02d8e29c6 Fix Bug#32084
da5d6dbe39 Fix (length NON-SEQUENCE) documentation

diff --cc doc/lispref/sequences.texi
Simple merge

diff --cc lisp/net/gnutls.el
Simple merge

diff --cc src/emacs.c
Simple merge