Provide add_timed_physim_test() in cmake

Add two new macros that allow to register physim tests for ctest,
including timing thresholds that should be fulfilled.

First, add_timed_physim_test() registers a new test using a helper
script RunTimedTest.cmake. This is because after test execution, we need
to analyze logs, and the recommended way to do multiple steps in one
test is via a helper cmake script:
https://cmake.org/pipermail/cmake-developers/2016-February/027816.html

Second, check_physim_threshold() adds new thresholds. It takes a text to
be parsed, and a condition (e.g., "< 20") to check for the number
following the threshold (which is assumed to be present right after the
threshold). It uses a test property to count the total number of checks
(limiting them to 10), and sets environment variables for the script.  I
initially planned to use a test property for checks, but those are only
valid in the same directory, and RunTimedTest.cmake seems to be assumed
by cmake to be "elsewhere", hence I needed to resort to environment
variables.

RunTimedTest.cmake is called through cmake with the test parameters and
checks. It re-constructs a list of checks [1], runs the test, and pipes
the log into a separate script that is passed all checks (see below).
Afterwards, it verifies that both the test and script passed.

A script analyze-timing.sh builds an awk script from the checks passed.
The script analyzes each line of the test output for the threshold, and
compares against the threshold. analyze-timing.sh returns success if all
checks passed.

[1] I did not manage to pass a "list" of checks in a single environment
variable through the check_physim_threshold(), which would be simpler.

openair1/SIMULATION/tests/RunTimedTest.cmake

@@ -0,0 +1,41 @@
+# this script expects
+# - TEST_CMD (program + options)
+# - CHECK_SCRIPT (path to analyze-timing.sh)
+# further, it analyzes the (test-specific) environment for CHECK_0, CHECK_1,
+# etc. to construct the input to the check script.
+
+# the calling process writes env vars CHECK_0, CHECK_1, ...
+# each has "condition;threshold" as it's content
+# combine all necessary CHECK0, CHECK1, ... into a single array CHECKS
+# to be passed to the check script
+foreach(count RANGE 9)
+  set(CHECK "CHECK_${count}")
+  if (NOT DEFINED ENV{${CHECK}})
+    break()
+  endif()
+  list(APPEND CHECKS "$ENV{${CHECK}}")
+endforeach()
+
+# execute the actual test command TEST_CMD and pipe its output into the
+# check script. Afterwards, check both commands return codes.
+execute_process(COMMAND ${TEST_CMD}
+                COMMAND ${CHECK_SCRIPT} ${CHECKS}
+                COMMAND_ECHO STDOUT
+                RESULTS_VARIABLE RET_CODES
+)
+list(LENGTH RET_CODES LEN_RET_CODES)
+if(NOT LEN_RET_CODES EQUAL 2)
+  message(SEND_ERROR "execute_process() did not run both commands!")
+endif()
+
+list(GET RET_CODES 0 TEST_RET_CODE)
+message(STATUS "test command finished with ${TEST_RET_CODE}")
+if(NOT ${TEST_RET_CODE} MATCHES "0")
+  message(SEND_ERROR " => test failed!")
+endif()
+
+list(GET RET_CODES 1 CHECK_RET_CODE)
+message(STATUS "check command finished with ${CHECK_RET_CODE}")
+if(NOT ${CHECK_RET_CODE} MATCHES "0")
+  message(SEND_ERROR " => check failed!")
+endif()