Merge pull request #5321 from drodriguez/lldb-swift-include-paths

[cmake][lldb] Fix header search path in unified builds

Author: compnerd

lldb/cmake/modules/LLDBConfig.cmake

@@ -181,8 +181,10 @@ include_directories("${CMAKE_CURRENT_BINARY_DIR}/../clang/include")
 if(NOT LLDB_BUILT_STANDALONE)
   if (LLVM_EXTERNAL_SWIFT_SOURCE_DIR)
     include_directories(${LLVM_EXTERNAL_SWIFT_SOURCE_DIR}/include)
+    include_directories(${LLVM_EXTERNAL_SWIFT_SOURCE_DIR}/stdlib/public/SwiftShims)
   else ()
     include_directories(${CMAKE_SOURCE_DIR}/tools/swift/include)
+    include_directories(${CMAKE_SOURCE_DIR}/tools/swift/stdlib/public/SwiftShims)
   endif ()
   include_directories("${CMAKE_CURRENT_BINARY_DIR}/../swift/include")
 else ()