Auto merge of rust-lang#109073 - michaelwoerister:limit-mingw-llvm-link-jobs, r=Mark-Simulacrum

Limit the number of parallel link jobs during LLVM build for mingw.

This PR is an attempt to unblock rust-lang#108355, which keeps failing while trying to link various LLVM artifacts on mingw runners. It looks like doing too many linking jobs might put too much load on the system? (Although I don't understand why the jobs are only failing for rust-lang#108355 while they seem to pass for others)

r? infra-ci

Author: bors

src/ci/run.sh

@@ -60,6 +60,14 @@ RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --enable-cargo-native-static"
 RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set rust.codegen-units-std=1"
 RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set dist.compression-profile=best"
 
+# When building for mingw, limit the number of parallel linker jobs during
+# the LLVM build, as not to run out of memory.
+# This is an attempt to fix the spurious build error tracked by
+# https://github.com/rust-lang/rust/issues/108227.
+if isWindows && [[ ${CUSTOM_MINGW-0} -eq 1 ]]; then
+    RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set llvm.link-jobs=4"
+fi
+
 # Only produce xz tarballs on CI. gz tarballs will be generated by the release
 # process by recompressing the existing xz ones. This decreases the storage
 # space required for CI artifacts.