[libc-commits] [libc] [libc] update host build docs (PR #120147)

[Nick Desaulniers via libc-commits]

================
@@ -208,3 +195,18 @@ invocation:
    Because the libc does not yet support dynamic linking, the -static parameter
    must be added to all clang invocations.
 
+
+You can make sure you're using the newly built toolchain by trying out features
+that aren't yet supported by the system toolchain, such as fixed point. The
+following is an example program that demonstrates the difference:
+
+.. code-block:: C
+
+   #include <stdio.h>
----------------
nickdesaulniers wrote:

Consider adding a comment of the exact command line invocation one would use to compile this example.

```suggestion
   // $ clang hello.c
   #include <stdio.h>
```
(or more flags if more are required). The point is to show that this newly bootstrapped toolchain can (or can't) use the new libc easily.

https://github.com/llvm/llvm-project/pull/120147