[BOLT][CMAKE] Bump minimum required CMake version to 3.14

[Amir]

Summary

Addresses https://github.com/llvm/llvm-project/issues/54099

[Amir]

It would be best to stick with LLVM CMake requirement (3.13.4) and rework the incompatible part.

[tschuett]

If you could ask for a cherry-pick into the 14.x. It would be great, if LLVM 14 would have consistent cmake version requirements.

[Amir]

In D120625#3349981, @tschuett wrote:

If you could ask for a cherry-pick into the 14.x. It would be great, if LLVM 14 would have consistent cmake version requirements.

OK, will do. https://reviews.llvm.org/D121012 is the compatible solution

bolt/CMakeLists.txt

+cmake_minimum_required(VERSION 3.14.0)
 include(ExternalProject)
 
 set(BOLT_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
 set(BOLT_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
 set(CMAKE_CXX_STANDARD 14)
 
 set(BOLT_ENABLE_RUNTIME OFF)
 if (CMAKE_HOST_SYSTEM_PROCESSOR MATCHES "x86_64")