[llvm] Fix the build on OpenBSD by removing LLVM_VERSION_SUFFIX from created shared library names

[brad]

Summary

This fixes building on OpenBSD. Having a string at the end of a filename (.e.g. libclang.so.15.0.0git) of a library like this is not valid and breaks linking.

https://github.com/llvm/llvm-project/issues/53932

[thieta]

If this fixes OpenBSD it looks fine I think. But I wonder if we shouldn't just do this if we are on OpenBSD, changing the SOVERSION has been fraught with problems before since people have scripts that expect certain layouts.

Without having more tests and more investigation I will only accept this if the change only happens on OpenBSD.

[thieta]

@brad is this something you still need for OpenBSD?

clang/tools/libclang/CMakeLists.txt

if (USE_VERSION_SCRIPT)
     if (${CMAKE_SYSTEM_NAME} MATCHES "SunOS")
       target_link_options(libclang PRIVATE "-Wl,-z,gnu-version-script-compat")
     endif()
     # Ensure that libclang.so gets rebuilt when the linker script changes.
     set_property(SOURCE ARCMigrate.cpp APPEND PROPERTY
                  OBJECT_DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/libclang.map)
 
     set_target_properties(libclang PROPERTIES
-                          VERSION ${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH}${LLVM_VERSION_SUFFIX}
+                          VERSION ${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH}
                           ${LIBCLANG_SOVERSION_ARG})
   endif()
 endif()
 
 if(INTERNAL_INSTALL_PREFIX)
   set(LIBCLANG_HEADERS_INSTALL_DESTINATION "${INTERNAL_INSTALL_PREFIX}/include")
 else()
   set(LIBCLANG_HEADERS_INSTALL_DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}")

llvm/cmake/modules/AddLLVM.cmake

if(ARG_SHARED)
     endif()
 
     # Set SOVERSION on shared libraries that lack explicit SONAME
     # specifier, on *nix systems that are not Darwin.
     if(UNIX AND NOT APPLE AND NOT ARG_SONAME)
       set_target_properties(${name}
         PROPERTIES
         # Since 4.0.0, the ABI version is indicated by the major version
-        SOVERSION ${LLVM_VERSION_MAJOR}${LLVM_VERSION_SUFFIX}
-        VERSION ${LLVM_VERSION_MAJOR}${LLVM_VERSION_SUFFIX})
+        SOVERSION ${LLVM_VERSION_MAJOR}
+        VERSION ${LLVM_VERSION_MAJOR})
     endif()
   endif()
 
   if(ARG_MODULE OR ARG_SHARED)
     # Do not add -Dname_EXPORTS to the command-line when building files in this
     # target. Doing so is actively harmful for the modules build because it
     # creates extra module variants, and not useful because we don't use these
     # macros.

llvm/tools/llvm-config/CMakeLists.txt

 set(LLVM_OBJ_ROOT ${LLVM_BINARY_DIR})
 set(LLVM_CPPFLAGS "${LLVM_DEFINITIONS}")
 set(LLVM_CFLAGS "${LLVM_C_STD_FLAG} ${LLVM_DEFINITIONS}")
 # The language standard potentially affects the ABI/API of LLVM, so we want
 # to make sure it is reported by llvm-config.
 set(LLVM_CXXFLAGS "${CMAKE_CXX${CMAKE_CXX_STANDARD}_STANDARD_COMPILE_OPTION} ${LLVM_CXX_STDLIB_FLAG} ${COMPILE_FLAGS} ${LLVM_DEFINITIONS}")
 set(LLVM_BUILD_SYSTEM cmake)
 set(LLVM_HAS_RTTI ${LLVM_CONFIG_HAS_RTTI})
-set(LLVM_DYLIB_VERSION "${LLVM_VERSION_MAJOR}${LLVM_VERSION_SUFFIX}")
+set(LLVM_DYLIB_VERSION "${LLVM_VERSION_MAJOR}")
 
 # Use the C++ link flags, since they should be a superset of C link flags.
 set(LLVM_LDFLAGS "${CMAKE_CXX_LINK_FLAGS}")
 set(LLVM_BUILDMODE ${CMAKE_BUILD_TYPE})
 set(LLVM_SYSTEM_LIBS ${SYSTEM_LIBS})
 string(REPLACE ";" " " LLVM_TARGETS_BUILT "${LLVM_TARGETS_TO_BUILD}")
 llvm_canonicalize_cmake_booleans(
   LLVM_BUILD_LLVM_DYLIB