message: [lit] Add swift support to toolchain.py
diff: @@ -97,6 +97,17 @@ def use_support_substitutions(config):
  elif platform.system() in ['OpenBSD', 'Linux']:
  flags = ['-pthread']
  + # Swift support
  + swift_sdk = [' -sdk ', sdk_path] if platform.system() in ['Darwin'] else []
  + tools = [
  + ToolSubst(
  + '%target-swiftc', command=config.swiftc, extra_args=swift_sdk),
  + ToolSubst(
  + '%target-swift-frontend',
  + command=config.swiftc[:-1],
  + extra_args=swift_sdk)
  + ]
  + llvm_config.add_tool_substitutions(tools)
  additional_tool_dirs=[]
  if config.lldb_lit_tools_dir:
  