Squashed 'vendor/ccut/' changes from e2c130c..002d404

002d404 add utility function ccut_trap_asserts()

git-subtree-dir: vendor/ccut
git-subtree-split: 002d40426b5176aef1a0642af8fbbb29ddc28010
Merge commit '2e3ad26e163f21e2f3435d4738cf480e540c1315'
trap <assert.h> failure and print stack trace when testing