Merge branch 'feature/andre/warn-libc-spec-insufficient' into 'master'

synchronize with frama-c/frama-c!1972

See merge request frama-c/e-acsl!240

src/plugins/e-acsl/tests/temporal/t_getenv.c

 /* run.config
    COMMENT: Check temporal validity of environment string (via getenv function)
+   STDOPT: #"-eva-warn-key=-libc:unsupported-spec"
 */
-
 #include <stdlib.h>
 #include <errno.h>