[libcxx-commits] [libcxx] [libcxx][docs] Note how to use just built libc++ with per-target runtimes layout (PR #172316)

[David Spickett via libcxx-commits]

DavidSpickett wrote:

CI failure is clearly unrelated:
```
lib/Support/CMakeFiles/LLVMSupport.dir/APFloat.cpp.o -c /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/lib/Support/APFloat.cpp
  /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/lib/Support/APFloat.cpp:32:10: fatal error: 'shared/math.h' file not found
     32 | #include "shared/math.h"
        |          ^~~~~~~~~~~~~~~
  1 error generated.
```
And has since been fixed on main.

https://github.com/llvm/llvm-project/pull/172316