Adjust support expectations for downloaded LLVMs

config.toml.example

@@ -36,8 +36,8 @@ changelog-seen = 1
 # toolchain or changing LLVM locally, you probably want to set this to true.
 #
 # It's currently false by default due to being newly added; please file bugs if
-# enabling this did not work for you on Linux (macOS and Windows support is
-# coming soon).
+# enabling this did not work for you on x86_64-unknown-linux-gnu.
+# Other target triples are currently not supported; see #77084.
 #
 # We also currently only support this when building LLVM for the build triple.
 #
@@ -380,7 +380,7 @@ changelog-seen = 1
 
 # Whether or not to leave debug! and trace! calls in the rust binary.
 # Overrides the `debug-assertions` option, if defined.
-# 
+#
 # Defaults to rust.debug-assertions value
 #debug-logging = debug-assertions