Rollup merge of #134124 - MarcoIeni:split-llvm-jobs, r=Kobzol

CI: use free runners for x86_64-gnu-llvm jobs

try-job: x86_64-gnu-llvm-19-1
try-job: x86_64-gnu-llvm-19-2
try-job: x86_64-gnu-llvm-19-3
try-job: x86_64-gnu-llvm-18-1
try-job: x86_64-gnu-llvm-18-2
try-job: x86_64-gnu-llvm-18-3

1 files changed, 19 insertions, 0 deletions

diff --git a/src/ci/docker/scripts/add_dummy_commit.sh b/src/ci/docker/scripts/add_dummy_commit.sh
new file mode 100755
index 00000000000..029e4ae141f
--- /dev/null
+++ b/src/ci/docker/scripts/add_dummy_commit.sh
@@ -0,0 +1,19 @@
+#!/bin/bash
+
+set -ex
+
+if [ "$READ_ONLY_SRC" = "0" ]; then
+    # `core::builder::tests::ci_rustc_if_unchanged_logic` bootstrap test ensures that
+    # "download-rustc=if-unchanged" logic don't use CI rustc while there are changes on
+    # compiler and/or library. Here we are adding a dummy commit on compiler and running
+    # that test to make sure we never download CI rustc with a change on the compiler tree.
+    echo "" >> ../compiler/rustc/src/main.rs
+    git config --global user.email "dummy@dummy.com"
+    git config --global user.name "dummy"
+    git add ../compiler/rustc/src/main.rs
+    git commit -m "test commit for rust.download-rustc=if-unchanged logic"
+    DISABLE_CI_RUSTC_IF_INCOMPATIBLE=0 ../x.py test bootstrap \
+        -- core::builder::tests::ci_rustc_if_unchanged_logic
+    # Revert the dummy commit
+    git reset --hard HEAD~1
+fi