types: add re_assert and re_assert_se definition

[sreimers]

cmake -B build -DCMAKE_BUILD_TYPE=Debug

int err;
re_assert(!(err = myfunc())); /* myfunc() is executed and assert() calls abort() if expr is false */
re_assert_se(!(err = myfunc())); /* myfunc() is executed and assert() calls abort() if expr is false  */

cmake -B build -DCMAKE_BUILD_TYPE=Release

int err;
re_assert(!(err = myfunc())); /* myfunc() and assert() are not executed in release builds */
re_assert_se(!(err = myfunc())); /* myfunc() is executed in release build (keeps side effect) but assert() is not called */