Fixes for standalone build:

* include CheckAtomic to set HAVE_CXX_ATOMICS64_WITHOUT_LIB properly (introduced in r274121)
* hint Clang CMake files for LLVM CMake files location (inctroduced in ~ r274176)

Differential revision: https://reviews.llvm.org/D22322

llvm-svn: 275641

lldb/cmake/modules/LLDBStandalone.cmake

@@ -58,6 +58,7 @@ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   set(LLVM_TOOLS_BINARY_DIR ${TOOLS_BINARY_DIR} CACHE PATH "Path to llvm/bin")
   set(LLVM_LIBRARY_DIR ${LIBRARY_DIR} CACHE PATH "Path to llvm/lib")
   set(LLVM_MAIN_INCLUDE_DIR ${INCLUDE_DIR} CACHE PATH "Path to llvm/include")
+  set(LLVM_DIR ${LLVM_OBJ_ROOT}/cmake/modules/CMakeFiles CACHE PATH "Path to LLVM build tree CMake files")
   set(LLVM_BINARY_DIR ${LLVM_OBJ_ROOT} CACHE PATH "Path to LLVM build tree")
   set(LLVM_MAIN_SRC_DIR ${MAIN_SRC_DIR} CACHE PATH "Path to LLVM source tree")
 
@@ -85,6 +86,7 @@ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
 
   include(AddLLVM)
   include(HandleLLVMOptions)
+  include(CheckAtomic)
 
   if (PYTHON_EXECUTABLE STREQUAL "")
     set(Python_ADDITIONAL_VERSIONS 3.5 3.4 3.3 3.2 3.1 3.0 2.7 2.6 2.5)