[CMake] Install FindLibEdit find module

This is a follow-up to D147153 and addresses CMake warnings about not
finding LibEdit find module when another project uses LLVM as a
dependency.

Fixes https://github.com/llvm/llvm-project/issues/62300

Reviewed By: Dinistro

Differential Revision: https://reviews.llvm.org/D148993

cmake/Modules/FindLibEdit.cmake

@@ -1,66 +0,0 @@
-#.rst:
-# FindLibEdit
-# -----------
-#
-# Find libedit library and headers
-#
-# The module defines the following variables:
-#
-# ::
-#
-#   LibEdit_FOUND          - true if libedit was found
-#   LibEdit_INCLUDE_DIRS   - include search path
-#   LibEdit_LIBRARIES      - libraries to link
-#   LibEdit_VERSION_STRING - version number
-
-find_package(PkgConfig QUIET)
-pkg_check_modules(PC_LIBEDIT QUIET libedit)
-
-find_path(LibEdit_INCLUDE_DIRS NAMES histedit.h HINTS ${PC_LIBEDIT_INCLUDE_DIRS})
-find_library(LibEdit_LIBRARIES NAMES edit HINTS ${PC_LIBEDIT_LIBRARY_DIRS})
-
-include(CheckIncludeFile)
-if(LibEdit_INCLUDE_DIRS AND EXISTS "${LibEdit_INCLUDE_DIRS}/histedit.h")
-  include(CMakePushCheckState)
-  cmake_push_check_state()
-  list(APPEND CMAKE_REQUIRED_INCLUDES ${LibEdit_INCLUDE_DIRS})
-  list(APPEND CMAKE_REQUIRED_LIBRARIES ${LibEdit_LIBRARIES})
-  check_include_file(histedit.h HAVE_HISTEDIT_H)
-  cmake_pop_check_state()
-  if (HAVE_HISTEDIT_H)
-    file(STRINGS "${LibEdit_INCLUDE_DIRS}/histedit.h"
-          libedit_major_version_str
-          REGEX "^#define[ \t]+LIBEDIT_MAJOR[ \t]+[0-9]+")
-    string(REGEX REPLACE "^#define[ \t]+LIBEDIT_MAJOR[ \t]+([0-9]+)" "\\1"
-            libedit_major_version "${libedit_major_version_str}")
-
-    file(STRINGS "${LibEdit_INCLUDE_DIRS}/histedit.h"
-          libedit_minor_version_str
-          REGEX "^#define[ \t]+LIBEDIT_MINOR[ \t]+[0-9]+")
-    string(REGEX REPLACE "^#define[ \t]+LIBEDIT_MINOR[ \t]+([0-9]+)" "\\1"
-            libedit_minor_version "${libedit_minor_version_str}")
-
-    set(LibEdit_VERSION_STRING "${libedit_major_version}.${libedit_minor_version}")
-  else()
-    set(LibEdit_INCLUDE_DIRS "")
-    set(LibEdit_LIBRARIES "")
-  endif()
-endif()
-
-include(FindPackageHandleStandardArgs)
-find_package_handle_standard_args(LibEdit
-                                  FOUND_VAR
-                                    LibEdit_FOUND
-                                  REQUIRED_VARS
-                                    LibEdit_INCLUDE_DIRS
-                                    LibEdit_LIBRARIES
-                                  VERSION_VAR
-                                    LibEdit_VERSION_STRING)
-mark_as_advanced(LibEdit_INCLUDE_DIRS LibEdit_LIBRARIES)
-
-if (LibEdit_FOUND AND NOT TARGET LibEdit::LibEdit)
-  add_library(LibEdit::LibEdit UNKNOWN IMPORTED)
-  set_target_properties(LibEdit::LibEdit PROPERTIES
-                        IMPORTED_LOCATION ${LibEdit_LIBRARIES}
-                        INTERFACE_INCLUDE_DIRECTORIES ${LibEdit_INCLUDE_DIRS})
-endif()