LineEndingsCheck: improve performance

LineEndingsCheck generally takes anywhere from 4 to 6 seconds to run,
depending on the size of the package. This change reduces the time to
run by ~53% as tested on packages in MU_BASECORE due to the following
changes:

1. Reorganized filters to reduce the amount of list comprehensions
   performed to filter out files that do not need to be checked

2. Organized the order of checks in regards to filters most likely to
   catch a file, and the expensiveness of the filter itself.

.pytool/Plugin/LineEndingCheck/LineEndingCheck.py

@@ -260,47 +260,27 @@ def RunBuildPlugin(self, package_rel_path: str, edk2_path: Edk2Path,
             tc.LogStdError(f"Package folder not found {self._abs_pkg_path}")
             return 0
 
-        all_files = [Path(n) for n in glob.glob(
-                        os.path.join(self._abs_pkg_path, '**/*.*'),
-                        recursive=True)]
-        ignored_files = list(filter(
-                            self._get_files_ignored_in_config(
-                                package_config, self._abs_pkg_path), all_files))
-        ignored_files = [Path(f) for f in ignored_files]
-
-        all_files = list(set(all_files) - set(ignored_files))
-        if not all_files:
-            tc.SetSuccess()
-            return 0
-
-        all_files_before_git_removal = set(all_files)
-        git_ignored_paths = set(self._get_git_ignored_paths() + self._get_git_submodule_paths())
-        all_files = list(all_files_before_git_removal - git_ignored_paths)
-        git_ignored_paths = git_ignored_paths - (all_files_before_git_removal - set(all_files))
-        if not all_files:
-            tc.SetSuccess()
-            return 0
-
-        git_ignored_paths = {p for p in git_ignored_paths if p.is_dir()}
-
-        ignored_files = []
-        for file in all_files:
-            for ignored_path in git_ignored_paths:
-                if Path(file).is_relative_to(ignored_path):
-                    ignored_files.append(file)
-                    break
-
-        all_files = list(set(all_files) - set(ignored_files))
-        if not all_files:
-            tc.SetSuccess()
-            return 0
+        # MU_CHANGE begin: Perf Improvements
+        ignore_files = set(self._get_git_ignored_paths())
+        ignore_dirs = set(self._get_git_submodule_paths())
+        ignore_filter = self._get_files_ignored_in_config(package_config, self._abs_pkg_path)
 
         file_count = 0
         line_ending_count = dict.fromkeys(LINE_ENDINGS, 0)
-
-        for file in all_files:
+        for file in Path(self._abs_pkg_path).rglob('*'):
             if file.is_dir():
                 continue
+
+            if any(file.is_relative_to(ignore_dir) for ignore_dir in ignore_dirs):
+                continue
+
+            if ignore_filter(file):
+                continue
+
+            if file in ignore_files:
+                continue
+
+        # MU_CHANGE end: Perf Improvements
             with open(file.resolve(), 'rb') as fb:
                 if not fb.readable() or _is_binary_string(fb.read(1024)):
                     continue
@@ -341,5 +321,4 @@ def RunBuildPlugin(self, package_rel_path: str, edk2_path: Edk2Path,
                 "CHECK_FAILED")
         else:
             tc.SetSuccess()
-
         return sum(line_ending_count.values())