CMake: carry over some nuances from autotools test config

Port more capabilities from Makefile.am:
  1. test-specific compilation flags
  2. support for lenient deadlines when running in the Swift CI
  3. extended test suite (tests we disable because they occasionally fail)
  4. list of not ported tests (Darwin-only functionality)

Author: dgrove-oss

tests/CMakeLists.txt

@@ -74,6 +74,11 @@ function(add_unit_test name)
                                ${CMAKE_CURRENT_BINARY_DIR}
                                ${CMAKE_CURRENT_SOURCE_DIR}
                                ${CMAKE_SOURCE_DIR})
+  if(CMAKE_SWIFT_COMPILER)
+	# For testing in swift.org CI system; make deadlines lenient by default
+	# to reduce probability of test failures due to machine load.
+	target_compile_options(${name} PRIVATE -DLENIENT_DEADLINES=1)
+  endif()
   if(WITH_BLOCKS_RUNTIME)
     target_include_directories(${name}
                                SYSTEM BEFORE PRIVATE
@@ -141,6 +146,34 @@ set(DISPATCH_C_TESTS
 set(DISPATCH_CPP_TESTS
     plusplus)
 
+# Tests that usually pass, but occasionally fail
+# and are therefore not suitable for general CI usage.
+if(EXTENDED_TEST_SUITE)
+  list(APPEND DISPATCH_C_TESTS
+	priority
+	concur
+	read
+	read2
+	suspend_timer
+	pingpong
+	drift
+	readsync
+	cascade
+	io)
+  # an oddball; dispatch_priority.c compiled with -DUSE_SET_TARGET_QUEUE=1
+  add_unit_test(dispatch_priority2 SOURCES dispatch_priority.c)
+  target_compile_options(dispatch_priority2 PRIVATE -DUSE_SET_TARGET_QUEUE=1)
+endif()
+
+# Tests for platform-specific functionality
+if(CMAKE_SYSTEM_NAME STREQUAL Darwin)
+  list(APPEND DISPATCH_C_TESTS
+	deadname
+	proc
+	vm
+	vnode)
+endif()
+
 foreach(test ${DISPATCH_C_TESTS})
   add_unit_test(dispatch_${test}
                 SOURCES
@@ -151,6 +184,10 @@ foreach(test ${DISPATCH_CPP_TESTS})
                 SOURCES
                   dispatch_${test}.cpp)
 endforeach()
+
+# test-specific link options
 target_link_libraries(dispatch_group PRIVATE m)
 target_link_libraries(dispatch_timer_short PRIVATE m)
 
+# test-specific compile options
+target_compile_options(dispatch_c99 PRIVATE -std=c99)