spec: adapted to https://altlinux.org/CMakeMigration2021

11.0.0 -> 11.0.1.
New LLVM subproject: lldb.

Installed to /usr/lib/llvm-11.0 to ensure peaceful co-existence with other
11.0/%_lib are symlinked to %_libdir
Moved clang-format and other clang-based tools to clang11.0-tools.
New LLVM subproject: clang-tools-extra.
tools, clangd11.0
Enabled all LLVM targets.
Moved C/C++ compiler support away from clang-libs to clang-libs-support.
Moved Clang .so runtimes (scudo and sanitizers) with available static variants
libs-support-shared-runtimes to comply with sisyphus-check-static.

11.0.0
Built with gcc.

Applied upstream patch which should fix ppc64le-specific issue.

10.0.1

add riscv64 support

10.0.0

use 'Release' build
clang: fixed link with option -fsanitize=address (closes: #38250)

build with clang

9.0.1

Added mipsel-alt-linux and ppc64le-alt-linux triples support.
lld:

Added patches from stable:
nm: Add --portability as alias for --format=posix.
objdump: Implement -z/--disassemble-zeroes.

Rebuild by clang7.0.

Bootstrap w/ gcc.

Updated to 7.0.1.
Split static library exports in cmake (patch from RH).
Build with clang.