[CMake] Remove redundant logic in runtimes/CMakeList.txt

Summary:
`SUB_CHECK_TARGETS` contains all test targets in `SUB_COMPONENTS` when
we load `Components.cmake`. We don't need to add those targets
again and having duplicate targets will break the cmake policy CMP0002.

Reviewers: phosek

Subscribers: mgorny, llvm-commits, srhines, pirama

Differential Revision: https://reviews.llvm.org/D35692

llvm-svn: 308900

llvm/runtimes/CMakeLists.txt

@@ -367,9 +367,6 @@ else() # if this is included from LLVM's CMake
 
       if(LLVM_INCLUDE_TESTS)
         list(APPEND test_targets runtimes-test-depends check-runtimes)
-        foreach(component ${SUB_COMPONENTS})
-          list(APPEND SUB_CHECK_TARGETS check-${component})
-        endforeach()
       endif()
 
       llvm_ExternalProject_Add(runtimes