Revise IDE folder structure (llvm#89755)

Update the folder titles for targets in the monorepository that have not
seen taken care of for some time. These are the folders that targets are
organized in Visual Studio and XCode
(`set_property(TARGET <target> PROPERTY FOLDER "<title>")`)
when using the respective CMake's IDE generator.

 * Ensure that every target is in a folder
 * Use a folder hierarchy with each LLVM subproject as a top-level folder
 * Use consistent folder names between subprojects
 * When using target-creating functions from AddLLVM.cmake, automatically
deduce the folder. This reduces the number of
`set_property`/`set_target_property`, but are still necessary when
`add_custom_target`, `add_executable`, `add_library`, etc. are used. A
LLVM_SUBPROJECT_TITLE definition is used for that in each subproject's
root CMakeLists.txt.

cross-project-tests/CMakeLists.txt

@@ -3,6 +3,7 @@
 # The subset inside debuginfo-tests invoke clang to generate programs with
 # various types of debug info, and then run those programs under a debugger
 # such as GDB or LLDB to verify the results.
+set(LLVM_SUBPROJECT_TITLE "Cross-Project")
 
 find_package(Python3 COMPONENTS Interpreter)
 
@@ -97,8 +98,3 @@ add_lit_testsuite(check-cross-amdgpu "Running AMDGPU cross-project tests"
 add_lit_testsuites(CROSS_PROJECT ${CMAKE_CURRENT_SOURCE_DIR}
   DEPENDS ${CROSS_PROJECT_TEST_DEPS}
   )
-
-set_target_properties(check-cross-project PROPERTIES FOLDER "Tests")
-set_target_properties(check-debuginfo PROPERTIES FOLDER "Tests")
-set_target_properties(check-intrinsic-headers PROPERTIES FOLDER "Tests")
-set_target_properties(check-cross-amdgpu PROPERTIES FOLDER "Tests")

libc/CMakeLists.txt

@@ -1,4 +1,5 @@
 cmake_minimum_required(VERSION 3.20.0)
+set(LLVM_SUBPROJECT_TITLE "libc")
 
 # Include LLVM's cmake policies.
 if(NOT DEFINED LLVM_COMMON_CMAKE_UTILS)

libcxx/CMakeLists.txt

@@ -5,6 +5,7 @@
 # Setup Project
 #===============================================================================
 cmake_minimum_required(VERSION 3.20.0)
+set(LLVM_SUBPROJECT_TITLE "libc++")
 
 set(LLVM_COMMON_CMAKE_UTILS "${CMAKE_CURRENT_SOURCE_DIR}/../cmake")
 

libcxxabi/CMakeLists.txt

@@ -5,6 +5,7 @@
 #===============================================================================
 
 cmake_minimum_required(VERSION 3.20.0)
+set(LLVM_SUBPROJECT_TITLE "libc++abi")
 
 set(LLVM_COMMON_CMAKE_UTILS "${CMAKE_CURRENT_SOURCE_DIR}/../cmake")
 

libunwind/CMakeLists.txt

@@ -3,6 +3,7 @@
 #===============================================================================
 
 cmake_minimum_required(VERSION 3.20.0)
+set(LLVM_SUBPROJECT_TITLE "libunwind")
 
 set(LLVM_COMMON_CMAKE_UTILS "${CMAKE_CURRENT_SOURCE_DIR}/../cmake")
 

llvm-libgcc/CMakeLists.txt

@@ -3,6 +3,7 @@
 #===============================================================================
 
 cmake_minimum_required(VERSION 3.20.0)
+set(LLVM_SUBPROJECT_TITLE "LLVM libgcc")
 
 set(LLVM_COMMON_CMAKE_UTILS "${CMAKE_CURRENT_SOURCE_DIR}/../cmake")
 

offload/CMakeLists.txt

@@ -2,6 +2,7 @@
 # to build offload with CMake.
 
 cmake_minimum_required(VERSION 3.20.0)
+set(LLVM_SUBPROJECT_TITLE "liboffload")
 
 if ("${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}")
   set(OPENMP_STANDALONE_BUILD TRUE)

pstl/CMakeLists.txt

@@ -6,6 +6,7 @@
 #
 #===----------------------------------------------------------------------===##
 cmake_minimum_required(VERSION 3.20.0)
+set(LLVM_SUBPROJECT_TITLE "Parallel STL")
 
 set(PARALLELSTL_VERSION_FILE "${CMAKE_CURRENT_SOURCE_DIR}/include/pstl/internal/pstl_config.h")
 file(STRINGS "${PARALLELSTL_VERSION_FILE}" PARALLELSTL_VERSION_SOURCE REGEX "#define _PSTL_VERSION .*$")

runtimes/CMakeLists.txt

@@ -9,6 +9,8 @@ include(${LLVM_COMMON_CMAKE_UTILS}/Modules/CMakePolicy.cmake
 include(${LLVM_COMMON_CMAKE_UTILS}/Modules/LLVMVersion.cmake)
 
 project(Runtimes C CXX ASM)
+set(LLVM_SUBPROJECT_TITLE "Runtimes")
+set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 
 list(INSERT CMAKE_MODULE_PATH 0
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake"