* lib/posix/execl.c (vexec): New function.
(execl): Use it.
* lib/posix/execlp.c: New file.
* build-aux/configure-lib.sh (libc_tcc_SOURCES): Add it.
* lib/libc+gnu.c: Include it.
* include/unistd.h (execlp): Declare.
* lib/tests/posix/90-execlp.c: New file.
* lib/tests/posix/90-execlp.stdout: New file.
* build-aux/check-mescc.sh: Test it.
