cram: Added test for invalid CLI flags

test/cram/help.t

@@ -49,3 +49,29 @@ Display the help message
       -OP:F or --output=PROVIDER=FILE: write test report to FILE using the specified provider
 
 
+Display usage on invalid CLI flags
+
+  $ simple.c.bin --an-invalid-option
+  simple.c.bin: unrecognized option '--an-invalid-option'
+  Tests compiled with Criterion v2.3.0-rc1
+  
+  usage: simple.c.bin OPTIONS
+  options: 
+      -h or --help: prints this message
+      -q or --quiet: disables all logging
+      -v or --version: prints the version of criterion these tests have been linked against
+      -l or --list: prints all the tests in a list
+      -jN or --jobs N: use N concurrent jobs
+      -f or --fail-fast: exit after the first failure
+      --ascii: don't use fancy unicode symbols or colors in the output
+      -S or --short-filename: only display the base name of the source file on a failure
+      --filter [PATTERN]: run tests matching the given pattern
+      --timeout [TIMEOUT]: set a timeout (in seconds) for all tests
+      --tap[=FILE]: writes TAP report in FILE (no file or "-" means stderr)
+      --xml[=FILE]: writes XML report in FILE (no file or "-" means stderr)
+      --always-succeed: always exit with 0
+      --verbose[=level]: sets verbosity to level (1 by default)
+      --crash: crash failing assertions rather than aborting (for debugging purposes)
+      --debug[=TYPE]: run tests with a debugging server, listening on localhost:1234 by default. TYPE may be gdb, lldb, or wingbd.
+      --debug-transport=VAL: the transport to use by the debugging server. `tcp:1234` by default
+      -OP:F or --output=PROVIDER=FILE: write test report to FILE using the specified provider