[RF][CMake] Make linking against ROOT::TestSupport explicit

Make linking against ROOT::TestSupport explicit if a RooFit test
requires it. This makes it possible to compile the tests in a standalone
build of RooFit when building against a ROOT build with `testing=OFF`.
One only has to add the test support library also as a target in the
RooFit build.

In any case, being explicit is always better.

Author: guitargeek

roofit/roofitcore/test/CMakeLists.txt

@@ -23,7 +23,7 @@ ROOT_ADD_GTEST(testRooAbsPdf testRooAbsPdf.cxx LIBRARIES RooFitCore)
 ROOT_ADD_GTEST(testRooAbsCollection testRooAbsCollection.cxx LIBRARIES RooFitCore)
 ROOT_ADD_GTEST(testRooDataSet testRooDataSet.cxx LIBRARIES Tree RooFitCore
   COPY_TO_BUILDDIR ${CMAKE_CURRENT_SOURCE_DIR}/dataSet_with_errors_6_26_10.root)
-ROOT_ADD_GTEST(testRooFormula testRooFormula.cxx LIBRARIES RooFitCore)
+ROOT_ADD_GTEST(testRooFormula testRooFormula.cxx LIBRARIES RooFitCore ROOT::TestSupport)
 ROOT_ADD_GTEST(testRooProdPdf testRooProdPdf.cxx LIBRARIES RooFitCore)
 ROOT_ADD_GTEST(testProxiesAndCategories testProxiesAndCategories.cxx
   LIBRARIES RooFitCore
@@ -72,11 +72,11 @@ ROOT_ADD_GTEST(testRooSTLRefCountList testRooSTLRefCountList.cxx LIBRARIES RooFi
 ROOT_ADD_GTEST(testRooSimultaneous testRooSimultaneous.cxx LIBRARIES RooFitCore)
 ROOT_ADD_GTEST(testRooTruthModel testRooTruthModel.cxx LIBRARIES RooFitCore RooFit)
 ROOT_ADD_GTEST(testSumW2Error testSumW2Error.cxx LIBRARIES Gpad RooFitCore)
-ROOT_ADD_GTEST(testTestStatistics testTestStatistics.cxx LIBRARIES RooFitCore)
+ROOT_ADD_GTEST(testTestStatistics testTestStatistics.cxx LIBRARIES RooFitCore ROOT::TestSupport)
 if (roofit_multiprocess)
   ROOT_ADD_GTEST(testTestStatisticsPlot TestStatistics/testPlot.cxx LIBRARIES RooFitMultiProcess RooFitCore RooFit
                    COPY_TO_BUILDDIR ${CMAKE_CURRENT_SOURCE_DIR}/TestStatistics/TestStatistics_ref.root)
-  ROOT_ADD_GTEST(testLikelihoodGradientJob TestStatistics/testLikelihoodGradientJob.cxx LIBRARIES RooFitMultiProcess RooFitCore m)
+  ROOT_ADD_GTEST(testLikelihoodGradientJob TestStatistics/testLikelihoodGradientJob.cxx LIBRARIES RooFitMultiProcess RooFitCore m ROOT::TestSupport)
   target_include_directories(testLikelihoodGradientJob PRIVATE ${RooFitCore_MultiProcess_TestStatistics_INCLUDE_DIR})
   ROOT_ADD_GTEST(testLikelihoodJob TestStatistics/testLikelihoodJob.cxx LIBRARIES RooFitMultiProcess RooFitCore m)
   target_include_directories(testLikelihoodJob PRIVATE ${RooFitCore_MultiProcess_TestStatistics_INCLUDE_DIR})