Revert "[cmake] Use `GNUInstallDirs` to support custom installation dirs."

Sorry for the disruption, I will try again later.

This reverts commit efeb50197091b2ade24c00b9d55814bc433a7fd1.

GitOrigin-RevId: 6e52bfe09d3ab3ae6c43c079d06ebeb7bb241dec
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7b8274a..2e73b6b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,4 @@
 include(CMakeDependentOption)
-include(GNUInstallDirs)
 
 option(CLANG_TIDY_ENABLE_STATIC_ANALYZER
   "Include static analyzer checks in clang-tidy" ON)
diff --git a/clang-doc/tool/CMakeLists.txt b/clang-doc/tool/CMakeLists.txt
index fb8317b..7e71478 100644
--- a/clang-doc/tool/CMakeLists.txt
+++ b/clang-doc/tool/CMakeLists.txt
@@ -19,9 +19,9 @@
   )
 
 install(FILES ../assets/clang-doc-default-stylesheet.css
-  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
+  DESTINATION share/clang
   COMPONENT clang-doc)
 
 install(FILES ../assets/index.js
-  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
+  DESTINATION share/clang
   COMPONENT clang-doc)
diff --git a/clang-include-fixer/find-all-symbols/tool/CMakeLists.txt b/clang-include-fixer/find-all-symbols/tool/CMakeLists.txt
index e6926a0..8f5509d 100644
--- a/clang-include-fixer/find-all-symbols/tool/CMakeLists.txt
+++ b/clang-include-fixer/find-all-symbols/tool/CMakeLists.txt
@@ -20,5 +20,5 @@
   )
 
 install(PROGRAMS run-find-all-symbols.py
-  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
+  DESTINATION share/clang
   COMPONENT find-all-symbols)
diff --git a/clang-include-fixer/tool/CMakeLists.txt b/clang-include-fixer/tool/CMakeLists.txt
index 5b9e00a..3936ac1 100644
--- a/clang-include-fixer/tool/CMakeLists.txt
+++ b/clang-include-fixer/tool/CMakeLists.txt
@@ -21,8 +21,8 @@
   )
 
 install(PROGRAMS clang-include-fixer.el
-  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
+  DESTINATION share/clang
   COMPONENT clang-include-fixer)
 install(PROGRAMS clang-include-fixer.py
-  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
+  DESTINATION share/clang
   COMPONENT clang-include-fixer)
diff --git a/clang-tidy/CMakeLists.txt b/clang-tidy/CMakeLists.txt
index 075e9f9..4556450 100644
--- a/clang-tidy/CMakeLists.txt
+++ b/clang-tidy/CMakeLists.txt
@@ -113,7 +113,7 @@
 
 if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
   install(DIRECTORY .
-    DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/clang-tidy"
+    DESTINATION include/clang-tidy
     COMPONENT clang-tidy-headers
     FILES_MATCHING
     PATTERN "*.h"
diff --git a/clang-tidy/tool/CMakeLists.txt b/clang-tidy/tool/CMakeLists.txt
index 4b8c938..ad3255b 100644
--- a/clang-tidy/tool/CMakeLists.txt
+++ b/clang-tidy/tool/CMakeLists.txt
@@ -52,9 +52,9 @@
 
 
 install(PROGRAMS clang-tidy-diff.py
-  DESTINATION "${CMAKE_INSTALL_DATADIR}/clang"
+  DESTINATION share/clang
   COMPONENT clang-tidy)
 install(PROGRAMS run-clang-tidy.py
-  DESTINATION "${CMAKE_INSTALL_BINDIR}"
+  DESTINATION bin
   COMPONENT clang-tidy
   RENAME run-clang-tidy)
diff --git a/modularize/CMakeLists.txt b/modularize/CMakeLists.txt
index fb17e35..4caae81 100644
--- a/modularize/CMakeLists.txt
+++ b/modularize/CMakeLists.txt
@@ -23,5 +23,5 @@
   )
 
 install(TARGETS modularize
-        RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}"
+        RUNTIME DESTINATION bin
         COMPONENT clang-extras)