Merge pull request #5190 from llvm-beanz/fix-xcode-generator-after-pr5182

[CMake] Fix the Xcode generator

Author: Chris B

cmake/modules/SwiftAddCustomCommandTarget.cmake

@@ -122,7 +122,9 @@ function(add_custom_command_target dependency_out_var_name)
   if("${ACCT_CUSTOM_TARGET_NAME}" STREQUAL "")
     # CMake doesn't allow '/' characters in filenames, so replace them with '-'
     list(GET ACCT_OUTPUT 0 output_filename)
-    string(REPLACE "/" "-" target_name "${output_filename}")
+    string(REPLACE "${CMAKE_BINARY_DIR}/" "" target_name "${output_filename}")
+    string(REPLACE "${CMAKE_CFG_INTDIR}/" "" target_name "${target_name}")
+    string(REPLACE "/" "-" target_name "${target_name}")
   else()
     set(target_name "${ACCT_CUSTOM_TARGET_NAME}")
   endif()