[CMake] Fix lld detection after D69685

[MaskRay]

Summary

D69685 actually broke lld detection for my build (probably due to CMake
processing order).

Before:

build projects/compiler-rt/lib/sanitizer_common/tests/Sanitizer-x86_64-Test-Nolibc: ... bin/clang || ...

After:

build projects/compiler-rt/lib/sanitizer_common/tests/Sanitizer-x86_64-Test-Nolibc: ... bin/clang bin/lld || ...

[rnk]

lgtm

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} ${TEST_LINK_FLAGS}")
     separate_arguments(TEST_LINK_FLAGS)
   endif()
-  if(NOT COMPILER_RT_STANDALONE_BUILD AND COMPILER_RT_HAS_LLD AND TARGET lld)
+  if(NOT COMPILER_RT_STANDALONE_BUILD AND COMPILER_RT_HAS_LLD AND "lld" IN_LIST LLVM_ENABLE_PROJECTS)
     # CMAKE_EXE_LINKER_FLAGS may contain -fuse=lld
     # FIXME: -DLLVM_ENABLE_LLD=ON and -DLLVM_ENABLE_PROJECTS without lld case.
     list(APPEND TEST_DEPS lld)
   endif()
   add_custom_command(
     OUTPUT "${output_bin}"
     COMMAND ${COMPILER_RT_TEST_COMPILER} ${TEST_OBJECTS} -o "${output_bin}"
             ${TEST_LINK_FLAGS}