Merge branch 'fix/libc/pthread_t_portability' into 'master'

doc/userman/user-changes.tex

doc/userman/user-sources.tex

share/libc/__fc_define_pthread_types.h

...ns/e-acsl/tests/concurrency/oracle/gen_parallel_threads.c

.../e-acsl/tests/concurrency/oracle/gen_sequential_threads.c

...ugins/e-acsl/tests/concurrency/oracle/gen_threads_debug.c

...csl/tests/concurrency/oracle/gen_threads_safe_locations.c

tests/libc/oracle/fc_libc.1.res.oracle

tests/libc/oracle/pthread_h.0.res.oracle

tests/libc/oracle/pthread_h.1.res.oracle

tests/libc/oracle/pthread_h.2.res.oracle

tests/libc/pthread_h.c