patch 9.1.1626: cindent: does not handle compound literals

patch 9.1.1626: cindent: does not handle compound literals

Problem:  C-indent does not handle compound literals
          (@44100hertz, @Jorenar)
Solution: Detect and handle compound literal and structure
          initialization (Anttoni Erkkilä)

match '=' or "return" optionally followed by &, (typecast), {
Fixes also initialization which begins with multiple opening braces.

fixes: #2090
fixes: #12491
closes: #17865

Signed-off-by: Anttoni Erkkilä <anttoni.erkkila@protonmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>