ctest_build: Use "cmake --build" to launch the native build tool

This avoids requiring cmGlobalGenerator::GenerateBuildCommand to produce
a string so that it can be later refactored to produce a vector with no
quoting or escaping.  It also makes the ctest_build command match what
"ctest -T Build" would run in a build tree configured with the new
build_command() command behavior.  It also ensures that the native build
tool used matches that selected by the configuration of the tree to be
built.

Source/CTest/cmCTestBuildCommand.cxx

@@ -114,9 +114,6 @@ cmCTestGenericHandler* cmCTestBuildCommand::InitializeHandler()
           this->Makefile->GetCMakeInstance()->CreateGlobalGenerator(
             cmakeGeneratorName);
         }
-      this->GlobalGenerator->FindMakeProgram(this->Makefile);
-      const char* cmakeMakeProgram
-        = this->Makefile->GetDefinition("CMAKE_MAKE_PROGRAM");
       if(strlen(cmakeBuildConfiguration) == 0)
         {
         const char* config = 0;
@@ -133,10 +130,8 @@ cmCTestGenericHandler* cmCTestBuildCommand::InitializeHandler()
       std::string dir = this->CTest->GetCTestConfiguration("BuildDirectory");
       std::string buildCommand
         = this->GlobalGenerator->
-        GenerateBuildCommand(cmakeMakeProgram,
-                             cmakeProjectName, dir.c_str(),
-                             cmakeBuildAdditionalFlags, cmakeBuildTarget,
-                             cmakeBuildConfiguration, true, false);
+        GenerateCMakeBuildCommand(cmakeBuildTarget, cmakeBuildConfiguration,
+                                  cmakeBuildAdditionalFlags, true);
       cmCTestLog(this->CTest, HANDLER_VERBOSE_OUTPUT,
                  "SetMakeCommand:"
                  << buildCommand.c_str() << "\n");