gstrvbuilder: Add a new object to make NULL-terminated string arrays.

GLib uses NULL-terminated string arrays (GStrv) in a number of places, however
these are quite hard to construct in C when the number of elements is not known
in advance. GStrvBuilder wraps GPtrArray to make these easy to create with
type safety and does the memory management for you.
14 jobs for strv-builder in 12 minutes and 11 seconds (queued for 1 second)
Status Job ID Name Coverage
  Style Check
passed #633475
check-todos

00:00:50

failed #633474
allowed to fail
style-check-diff

00:00:55

 
  Build
passed #633480
cross-android_api21_arm64

00:01:17

passed #633481
cross-android_api28_arm64

00:01:36

passed #633482
cross-mingw64

00:02:05

passed #633477
debian-stable-x86_64

00:02:15

failed #633476
fedora-x86_64

00:10:19

passed #633479
G_DISABLE_ASSERT

00:04:13

passed #633478
installed-tests

00:04:24

passed #633483
win32
msys2-mingw32

00:11:16

passed #633484
win32
vs2017-x64

00:08:42

 
  Coverage
skipped #633485
coverage
 
  Analysis
skipped #633487
scan-build
skipped #633486
allowed to fail
valgrind
 
Name Stage Failure
failed
fedora-x86_64 Build
_build/docs/reference/gio/gio-undocumented.txt: found 1 matching files 
_build/docs/reference/gio/gio-unused.txt: found 1 matching files

_build/fedora-x86_64-report.xml: found 1 matching files

_coverage: found 2 matching files

Uploading artifacts to coordinator... ok
id=633476 responseStatus=201 Created token=mr8jaFeE
Uploading artifacts...
_build/fedora-x86_64-report.xml: found 1 matching files

Uploading artifacts to coordinator... ok
id=633476 responseStatus=201 Created token=mr8jaFeE
ERROR: Job failed: exit code 1
failed
style-check-diff Style Check
 }

int
-main (int argc,
+main (int argc,
char *argv[])
{
g_test_init (&argc, &argv, NULL);
ERROR: Job failed: exit code 1