Backport "Add cmake to source release tarballs" to 14.x

[mati865]

Could 32a0482 be backported to 14.x ?
I think it's rather critical because without it trying to build various LLVM projects from tarballs fails with errors like:

CMake Error at D:/Projekty/msys2/MINGW-packages/mingw-w64-clang/src/compiler-rt/CMakeLists.txt:31 (include):
  include could not find requested file:

    SetPlatformToolchainTools


CMake Error at D:/Projekty/msys2/MINGW-packages/mingw-w64-clang/src/compiler-rt/cmake/base-config-ix.cmake:9 (include):
  include could not find requested file:

    ExtendPath

First noticed it with LLVM 14 RC1 but seeing the fix was in the works I though it would be fixed with RC2. It's not the case though and IIUC backporting that commit should fix building from tarballs for the next RC/release.

[h-vetinari]

It doesn't cherry-pick cleanly, but there's a backport waiting in llvmbot#110, see also #53281

[mati865]

Sorry couldn't find it due to different error order. Should I close this one?

[h-vetinari]

Backport happened (thanks!), so this can be closed. :)

[mati865]

Thank you!

[tstellar]

Merged: 1e3d5cc

[rubyFeedback]

Just ran into this issue. Could a new minor 14.x release be made with the fix? Somehow the more recent cmake versions seemed to have issues, whereas I think I remember having compiled llvm just fine with an older cmake version.

Edit: the error was

-- Performing Test CXX_SUPPORTS_NO_NESTED_ANON_TYPES_FLAG - Failed
-- Looking for include file sys/inotify.h
-- Looking for include file sys/inotify.h - found
-- Not building amdgpu-arch: hsa-runtime64 not found
CMake Error at tools/clang/cmake/modules/CMakeLists.txt:1 (include):
  include could not find requested file:

    ExtendPath


CMake Error at tools/clang/cmake/modules/CMakeLists.txt:3 (include):
  include could not find requested file:

    FindPrefixFromConfig

CMake Error at tools/clang/cmake/modules/CMakeLists.txt:42 (find_prefix_from_config):
  Unknown CMake command "find_prefix_from_config".

[seppeon]

Just ran into this issue. Could a new minor 14.x release be made with the fix? Somehow the more recent cmake versions seemed to have issues, whereas I think I remember having compiled llvm just fine with an older cmake version.

Edit: the error was

-- Performing Test CXX_SUPPORTS_NO_NESTED_ANON_TYPES_FLAG - Failed
-- Looking for include file sys/inotify.h
-- Looking for include file sys/inotify.h - found
-- Not building amdgpu-arch: hsa-runtime64 not found
CMake Error at tools/clang/cmake/modules/CMakeLists.txt:1 (include):
  include could not find requested file:

    ExtendPath


CMake Error at tools/clang/cmake/modules/CMakeLists.txt:3 (include):
  include could not find requested file:

    FindPrefixFromConfig

CMake Error at tools/clang/cmake/modules/CMakeLists.txt:42 (find_prefix_from_config):
  Unknown CMake command "find_prefix_from_config".

We have the same issue when trying to build compiler-rt-15.0.2.src.tar.xz