[debuginfo] Remove temporary FIXME.

[hintonda]

Summary

Now that r320495, "[debuginfo-tests] Support moving
debuginfo-tests to llvm/projects," has landed, remove temporary FIXME
that supported the old mechanism.

[aprantl]

I suppose this is fine, please check on the green dragon builders after committing to make sure there's no unexpected fallout.

test/lit.cfg.py

 
 # suffixes: A list of file extensions to treat as test files.
 config.suffixes = ['.c', '.cpp', '.cppm', '.m', '.mm', '.cu',
                    '.ll', '.cl', '.s', '.S', '.modulemap', '.test', '.rs']
 
 # excludes: A list of directories to exclude from the testsuite. The 'Inputs'
 # subdirectories contain auxiliary inputs for various tests in their parent
 # directories.
-config.excludes = ['Inputs', 'CMakeLists.txt', 'README.txt', 'LICENSE.txt']
+config.excludes = ['Inputs', 'CMakeLists.txt', 'README.txt', 'LICENSE.txt', 'debuginfo-tests']
 
 # test_source_root: The root path where tests are located.
 config.test_source_root = os.path.dirname(__file__)
 
 # test_exec_root: The root path where tests should be run.
 config.test_exec_root = os.path.join(config.clang_obj_root, 'test')
 
 llvm_config.use_default_substitutions()

 tool_dirs = [config.clang_tools_dir, config.llvm_tools_dir]
 
 tools = [
     'c-index-test', 'clang-check', 'clang-diff', 'clang-format', 'opt',
     ToolSubst('%clang_func_map', command=FindTool(
         'clang-func-mapping'), unresolved='ignore'),
 ]
 
-# FIXME: This logic can be removed once all buildbots have moved
-# debuginfo-test from clang/test to llvm/projects or monorepo.
-if os.path.exists(os.path.join(config.test_source_root, 'debuginfo-tests')):
-  if os.path.isfile(
-      os.path.join(config.test_source_root, 'debuginfo-tests', 'lit.cfg.py')):
-    config.excludes.append('debuginfo-tests')
-  else:
-    tools.append(ToolSubst('%test_debuginfo', command=os.path.join(
-      config.llvm_src_root, 'utils', 'test_debuginfo.pl')))
-
 if config.clang_examples:
     tools.append('clang-interpreter')
 
 llvm_config.add_tool_substitutions(tools, tool_dirs)
 
 # Plugins (loadable modules)
 # TODO: This should be supplied by Makefile or autoconf.
 if sys.platform in ['win32', 'cygwin']: