1f75f318ae
In some situations such as reported at https://github.com/llvm/llvm-project/pull/177953#issuecomment-4179014239, LLVM_(DEFAULT_)TARGET_TRIPLE is not set. It is used to derive the output directory in #177953. Only flang-rt currently uses RUNTIMES_(INSTALL|OUTPUT)_RESOURCE_LIB_PATH, we should not fail building other despite a missing LLVM_TARGET_TRIPLE. Compiler-rt uses COMPILER_RT_DEFAULT_TARGET_TRIPLE instead which it derives itself. Most other LLVM runtimes libraries just skip the target portion of the library path (explicitly so since #93354). Do the same for RUNTIMES_(INSTALL|OUTPUT)_RESOURCE_LIB_PATH which we hope eventually can replace the other mechanisms.