[llvm] [libc][bazel] Use Bazel aspects to implement libc_release_library. (PR #134948)

[Jordan Rupprecht via llvm-commits]

================
@@ -138,15 +189,18 @@ def libc_release_library(
         **kwargs: Other arguments relevant to cc_library.
     """
 
-    # Combine all sources into a single filegroup to avoid repeated sources error.
-    native.filegroup(
+    get_libc_srcs(
----------------
rupprecht wrote:

Having the rule name end in `_filegroup` would make this more familiar & obvious that it's basically creating a filegroup. Otherwise, it looks like this is a bug where you're getting a list of sources but not using the result, e.g. you should be writing `srcs = get_libc_srcs(...)`.

I went w/ `transitive_srcs_filegroup` for a similar rule, but maybe `libc_srcs_filegroup()` would be better here? Or `all_libc_files_filegroup()`?

https://github.com/llvm/llvm-project/pull/134948