[all-commits] [llvm/llvm-project] 2724d9: build: remove `LLVM_CXX_STD` extension point

[Saleem Abdulrasool via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 2724d9e12960cc1d93eeabbfc9aa1bffffa041cc
      https://github.com/llvm/llvm-project/commit/2724d9e12960cc1d93eeabbfc9aa1bffffa041cc
  Author: Saleem Abdulrasool <compnerd at compnerd.org>
  Date:   2019-10-25 (Fri, 25 Oct 2019)

  Changed paths:
    M llvm/CMakeLists.txt
    M llvm/cmake/modules/HandleLLVMOptions.cmake
    M llvm/docs/CMake.rst

  Log Message:
  -----------
  build: remove `LLVM_CXX_STD` extension point

This extension point is not needed. Provide the equivalent option
through `CMAKE_CXX_STANDARD` which mirrors the previous extension point. Rely on
CMake to provide the check for the compiler instead.