[cmake][lldb][test] Respect LIBCXX_LIBDIR_SUBDIR (llvm#159106)

This code in principle needs to match the one in libc++ but hasn't been updated to account for
LIBCXX_LIBDIR_SUBDIR so tests don't work if LLVM is built with it specified.

Fixes: ed155f3

Author: tambry

lldb/test/CMakeLists.txt

@@ -164,9 +164,14 @@ if(TARGET clang)
   if (TARGET libcxx OR ("libcxx" IN_LIST LLVM_ENABLE_RUNTIMES))
     set(LLDB_HAS_LIBCXX ON)
     if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
-      set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE})
+      set(LIBCXX_TARGET_SUBDIR ${LLVM_DEFAULT_TARGET_TRIPLE})
+      if(LIBCXX_LIBDIR_SUBDIR)
+        string(APPEND LIBCXX_TARGET_SUBDIR /${LIBCXX_LIBDIR_SUBDIR})
+      endif()
+      cmake_path(NORMAL_PATH LIBCXX_TARGET_SUBDIR)
+      set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LIBCXX_TARGET_SUBDIR})
       set(LIBCXX_GENERATED_INCLUDE_DIR "${LLVM_BINARY_DIR}/include/c++/v1")
-      set(LIBCXX_GENERATED_INCLUDE_TARGET_DIR "${LLVM_BINARY_DIR}/include/${LLVM_DEFAULT_TARGET_TRIPLE}/c++/v1")
+      set(LIBCXX_GENERATED_INCLUDE_TARGET_DIR "${LLVM_BINARY_DIR}/include/${LIBCXX_TARGET_SUBDIR}/c++/v1")
     else()
       set(LIBCXX_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXX_LIBDIR_SUFFIX})
       set(LIBCXX_GENERATED_INCLUDE_DIR "${CMAKE_BINARY_DIR}/include/c++/v1")

lldb/utils/lldb-dotest/CMakeLists.txt

@@ -15,9 +15,14 @@ llvm_canonicalize_cmake_booleans(
 if ("libcxx" IN_LIST LLVM_ENABLE_RUNTIMES)
   set(LLDB_HAS_LIBCXX ON)
   if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
-    set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE})
+    set(LIBCXX_TARGET_SUBDIR ${LLVM_DEFAULT_TARGET_TRIPLE})
+    if(LIBCXX_LIBDIR_SUBDIR)
+      string(APPEND LIBCXX_TARGET_SUBDIR /${LIBCXX_LIBDIR_SUBDIR})
+    endif()
+    cmake_path(NORMAL_PATH LIBCXX_TARGET_SUBDIR)
+    set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LIBCXX_TARGET_SUBDIR})
     set(LIBCXX_GENERATED_INCLUDE_DIR "${LLVM_BINARY_DIR}/include/c++/v1")
-    set(LIBCXX_GENERATED_INCLUDE_TARGET_DIR "${LLVM_BINARY_DIR}/include/${LLVM_DEFAULT_TARGET_TRIPLE}/c++/v1")
+    set(LIBCXX_GENERATED_INCLUDE_TARGET_DIR "${LLVM_BINARY_DIR}/include/${LIBCXX_TARGET_SUBDIR}/c++/v1")
   else()
     set(LIBCXX_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXX_LIBDIR_SUFFIX})
     set(LIBCXX_GENERATED_INCLUDE_DIR "${CMAKE_BINARY_DIR}/include/c++/v1")