[libc-commits] [libc] [libc] Redo the install targets (PR #78795)

[Joseph Huber via libc-commits]

jhuber6 wrote:

```
[4/4] cd /home/jhuber/Documents/llvm/llvm-project/build/runtimes/runtimes-bins/libc/lib && /usr/bin/cmake -DCMAKE_INSTALL_COMPONENT=libc -P /cmake_install.cmake
FAILED: libc/lib/CMakeFiles/install-libc /home/jhuber/Documents/llvm/llvm-project/build/runtimes/runtimes-bins/libc/lib/CMakeFiles/install-libc 
cd /home/jhuber/Documents/llvm/llvm-project/build/runtimes/runtimes-bins/libc/lib && /usr/bin/cmake -DCMAKE_INSTALL_COMPONENT=libc -P /cmake_install.cmake
CMake Error: Not a file: /cmake_install.cmake
CMake Error: Error processing file: /cmake_install.cmake
ninja: build stopped: subcommand failed.
FAILED: runtimes/CMakeFiles/install-libc /home/jhuber/Documents/llvm/llvm-project/build/runtimes/CMakeFiles/install-libc 
cd /home/jhuber/Documents/llvm/llvm-project/build/runtimes/runtimes-bins && /usr/bin/cmake --build /home/jhuber/Documents/llvm/llvm-project/build/runtimes/runtimes-bins/ --target install-libc --config Release
ninja: build stopped: subcommand failed.
```
This patch definitely didn't update something that it expects.

https://github.com/llvm/llvm-project/pull/78795