Fill in PR number

Author: Kobzol

src/bootstrap/download-ci-gcc-stamp

@@ -1,4 +1,4 @@
 Change this file to make users of the `download-ci-gcc` configuration download
 a new version of GCC from CI, even if the GCC submodule hasn’t changed.
 
-Last change is for: TODO
+Last change is for: https://github.com/rust-lang/rust/pull/138051

src/bootstrap/src/utils/change_tracker.rs

@@ -366,7 +366,7 @@ pub const CONFIG_CHANGE_HISTORY: &[ChangeInfo] = &[
         summary: "`rust.channel` now supports \"auto-detect\" to load the channel from `src/ci/channel`",
     },
     ChangeInfo {
-        change_id: 0,
+        change_id: 138051,
         severity: ChangeSeverity::Info,
         summary: "There is now a new `gcc` config section that can be used to download GCC from CI using `gcc.download-ci-gcc = true`",
     },