Merge from origin/emacs-25

Merge from origin/emacs-25

50fa7d6 ;* src/w32heap.c: Fix typo and wording of the comments.
6f1325e electric-quote mode no longer worries about coding
c2a1792 * src/regex.c (re_search_2): Make new code safe for -Wjump-mi...
f6134bb Port to GCC 6.2.1 + --enable-gcc-warnings
b2ba630 Explain how to debug emacsclient lisp errors
9da53e2 Let describe-function work for lambda again
5c2da93 Fix kill-line's docstring
ad66b3f Fix handling of allocation in regex matching
5a26c9b * lisp/electric.el (electric-quote-mode): Improve doc (Bug#24...
3877c91 vc-region-history: Search just on lines intersecting the region
8988327 Fix documentation of 'alist-get'
b6998ea * src/regex.h (re_match_object): Improve commentary.

# Conflicts:
#	etc/NEWS
#	lisp/help-fns.el