[cmake] Revert the change in subdir adds

We need to add the test directories after lib/include/tools so that
the test cmake files can access target [properties] of the code which
they are testing.

Author: teqdruid

CMakeLists.txt

@@ -187,7 +187,7 @@ set(CIRCT_TOOLS_INSTALL_DIR "${CMAKE_INSTALL_BINDIR}" CACHE PATH
     "Path for binary subdirectory (defaults to '${CMAKE_INSTALL_BINDIR}')")
 
 option(CIRCT_INCLUDE_TESTS
-       "Generate build targets for the CIRCT unit tests." ON)
+       "Generate build targets for the CIRCT tests." ON)
 
 list(APPEND CMAKE_MODULE_PATH "${MLIR_MAIN_SRC_DIR}/cmake/modules")
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules")
@@ -623,19 +623,25 @@ endif()
 
 if (CIRCT_INCLUDE_TESTS)
   add_definitions(-DCIRCT_INCLUDE_TESTS)
-  if (CIRCT_GTEST_AVAILABLE)
-    add_subdirectory(unittests)
-  endif()
-  add_subdirectory(test)
-  add_subdirectory(integration_test)
 endif()
+
 add_subdirectory(include/circt)
 add_subdirectory(lib)
 if(CIRCT_INCLUDE_TOOLS)
   add_subdirectory(tools)
 endif()
 add_subdirectory(frontends)
 
+if (CIRCT_INCLUDE_TESTS)
+  # Test directories are added after everything else so their cmake files can
+  # use targets and target properties defined by the things they test.
+  if (CIRCT_GTEST_AVAILABLE)
+    add_subdirectory(unittests)
+  endif()
+  add_subdirectory(test)
+  add_subdirectory(integration_test)
+endif()
+
 option(CIRCT_INCLUDE_DOCS "Generate build targets for the CIRCT docs.")
 if (CIRCT_INCLUDE_DOCS)
   add_subdirectory(docs)