COMP: Fix language feature introspection for SEM

Configuring with clang version 6.0.0 would fail with
error message:

CMake Error at (target_compile_features):
  target_compile_features no known features for CXX compiler

  "Clang"

  version 6.0.0.

This is related to reported issues, and suggested solution in:

https://gitlab.kitware.com/cmake/cmake/issues/17712
https://gitlab.kitware.com/cmake/cmake/issues/17714

The canonical top-level CMakeLists.txt file should be:

cmake_minimum_required(VERSION 3.10) # or some other version
project(MyProject) # optionally list languages or use NONE to suppress them

Author: hjmjohnson

CMakeLists.txt

@@ -1,7 +1,28 @@
-project(SlicerExecutionModel)
-
 #-----------------------------------------------------------------------------
-cmake_minimum_required(VERSION 2.8.6)
+cmake_minimum_required(VERSION 3.5)
+foreach(p
+  ## Only policies introduced after the cmake_minimum_required
+  ## version need to explicitly be set to NEW.
+#Policies Introduced by CMake 3.11
+CMP0072  # FindOpenGL prefers GLVND by default when available.
+#Policies Introduced by CMake 3.10
+CMP0071  # Let AUTOMOC and AUTOUIC process GENERATED files.
+CMP0070  # Define file(GENERATE) behavior for relative paths.
+#Policies Introduced by CMake 3.9
+CMP0069  # INTERPROCEDURAL_OPTIMIZATION is enforced when enabled.
+CMP0068  # RPATH settings on macOS do not affect install_name.
+#Policies Introduced by CMake 3.8
+CMP0067  # Honor language standard in try_compile() source-file signature.
+#Policies Introduced by CMake 3.7
+CMP0066  # Honor per-config flags in try_compile() source-file signature.
+  )
+  if(POLICY ${p})
+    cmake_policy(SET ${p} NEW)
+  endif()
+endforeach()
+
+project(SlicerExecutionModel CXX)
+
 #-----------------------------------------------------------------------------
 
 include(CMakeDependentOption)

GenerateCLP/CMakeLists.txt

@@ -1,8 +1,7 @@
-project(GenerateCLP)
-
 #-----------------------------------------------------------------------------
-cmake_minimum_required(VERSION 2.8.6)
+cmake_minimum_required(VERSION 3.5)
 #-----------------------------------------------------------------------------
+project(GenerateCLP)
 
 #-----------------------------------------------------------------------------
 # Set a default build type if none was specified

GenerateCLP/Testing/CLPExample1/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 2.8.6)
+cmake_minimum_required(VERSION 3.5)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../CMake/GenerateCLPTestMacros.cmake)
 

GenerateCLP/Testing/CLPTestMultiple/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 2.8.6)
+cmake_minimum_required(VERSION 3.5)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../CMake/GenerateCLPTestMacros.cmake)
 

GenerateCLP/Testing/PointExample1/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 2.8.6)
+cmake_minimum_required(VERSION 3.5)
 
 #-----------------------------------------------------------------------------
 # Configure & Build

GenerateCLP/Testing/Slicer3Example/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 2.8.6)
+cmake_minimum_required(VERSION 3.5)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/../CMake/GenerateCLPTestMacros.cmake)
 

ModuleDescriptionParser/CMakeLists.txt

@@ -1,8 +1,7 @@
-project(ModuleDescriptionParser)
-
 #-----------------------------------------------------------------------------
-cmake_minimum_required(VERSION 2.8.6)
+cmake_minimum_required(VERSION 3.5)
 #-----------------------------------------------------------------------------
+project(ModuleDescriptionParser CXX)
 
 #-----------------------------------------------------------------------------
 # Set a default build type if none was specified

tclap/CMakeLists.txt

@@ -1,8 +1,7 @@
-project(TCLAP)
-
 #-----------------------------------------------------------------------------
-cmake_minimum_required(VERSION 2.8.6)
+cmake_minimum_required(VERSION 3.5)
 #-----------------------------------------------------------------------------
+project(TCLAP)
 
 # --------------------------------------------------------------------------
 # Install headers