[llvm] [CMake] Check objcopy support for LLVM_SPLIT_DWARF (PR #80500)

[Jinsong Ji via llvm-commits]

jsji wrote:

> which roughly corresponds to the binutils 2.30 era

*roughly*?   I don't think we can assume that users are using binutils and GCC from *same era*. eg: Users can still use an old OS with old binutils, but just install newer GCC.



> https://llvm.org/docs/GettingStarted.html#host-c-toolchain-both-compiler-and-standard-library
> 
> GNU binutils 2.17: Binutils 2.17 contains [a bug](http://sourceware.org/bugzilla/show_bug.cgi?id=3111) which causes huge link times (minutes instead of seconds) when building LLVM. We recommend upgrading to a newer version (2.17.50.0.4 or later).

We actually distinguished GCC and binutils, and only require 2.17 .



> The default R_X86_64_REX_GOTPCRELX clang emits requires something like binutils 2.25+.

If this is the case, should we at least update the document above to mention we require 2.25+ ?



https://github.com/llvm/llvm-project/pull/80500