Prevent adding lld to test dependency (TEST_DEPS) when lld project is not built

[anhtuyen]

Summary

https://reviews.llvm.org/D69405 added

check_linker_flag("-fuse-ld=lld" COMPILER_RT_HAS_FUSE_LD_LLD_FLAG)

into compiler-rt/cmake/config-ix.cmake.

And, if the compiler used to build llvm can support -fuse-ld=lld, then COMPILER_RT_HAS_LLD will be set on line 500 of compiler-rt/CMakeLists.txt.

set(COMPILER_RT_HAS_LLD ${COMPILER_RT_HAS_FUSE_LD_LLD_FLAG})

The changes above then adds lld into the TEST_DEPS dependency online 471 of compiler-rt/cmake/Modules/AddCompilerRT.cmake

if(NOT COMPILER_RT_STANDALONE_BUILD AND COMPILER_RT_HAS_LLD)
  # CMAKE_EXE_LINKER_FLAGS may contain -fuse=lld
  # FIXME: -DLLVM_ENABLE_LLD=ON and -DLLVM_ENABLE_PROJECTS without lld case.
  list(APPEND TEST_DEPS lld)
endif()

This will cause failure if running LIT when the compiler was built without lld.

ninja: error: 'llvm/compiler-rt/lib/asan/tests/lld', needed by 'projects/compiler-rt/lib/asan/tests/dynamic/Asan-powerpc64le-calls-Dynamic-Test', missing and no known rule to make it

The patch is to fix the above-mentioned problem.

[eugenis]

LGTM, sorry I've missed this case

[anhtuyen]

Thank you very much Evgenii @eugenis for your prompt review and approval!

compiler-rt/cmake/Modules/AddCompilerRT.cmake

function(add_compiler_rt_test test_suite test_name arch)
   # link programs at all are included, but the changes needed for the test
   # trump. With MSVC we can't do that because CMake is set up to run link.exe
   # when linking, not the compiler. Here, we hack it to use the compiler
   # because we want to use -fsanitize flags.
   if(NOT MSVC)
     set(TEST_LINK_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${TEST_LINK_FLAGS}")
     separate_arguments(TEST_LINK_FLAGS)
   endif()
-  if(NOT COMPILER_RT_STANDALONE_BUILD AND COMPILER_RT_HAS_LLD)
+  if(NOT COMPILER_RT_STANDALONE_BUILD AND COMPILER_RT_HAS_LLD AND TARGET lld)
     # CMAKE_EXE_LINKER_FLAGS may contain -fuse=lld
     # FIXME: -DLLVM_ENABLE_LLD=ON and -DLLVM_ENABLE_PROJECTS without lld case.
     list(APPEND TEST_DEPS lld)
   endif()
   add_custom_command(
     OUTPUT "${output_bin}"
     COMMAND ${COMPILER_RT_TEST_COMPILER} ${TEST_OBJECTS} -o "${output_bin}"
             ${TEST_LINK_FLAGS}