Auto merge of #77372 - jonas-schievink:rollup-e5bdzga, r=jonas-schievink

Rollup of 12 pull requests

Successful merges:

 - #77037 (more tiny clippy cleanups)
 - #77233 (BTreeMap: keep an eye out on the size of the main components)
 - #77280 (Ensure that all LLVM components requested by tests are available on CI)
 - #77284 (library: Forward compiler-builtins "mem" feature)
 - #77296 (liveness: Use Option::None to represent absent live nodes)
 - #77322 (Add unstable book docs for `-Zunsound-mir-opts`)
 - #77328 (Use `rtassert!` instead of `assert!` from the child process after fork() in std::sys::unix::process::Command::spawn())
 - #77331 (Add test for async/await combined with const-generics.)
 - #77338 (Fix typo in alloc vec comment)
 - #77340 (Alloc vec use imported path)
 - #77345 (Add test for issue #74761)
 - #77348 (Update books)

Failed merges:

r? `@ghost`

1 files changed, 5 insertions, 2 deletions

diff --git a/src/tools/compiletest/src/header.rs b/src/tools/compiletest/src/header.rs
index 17649dfab37..59f64e7df0f 100644
--- a/src/tools/compiletest/src/header.rs
+++ b/src/tools/compiletest/src/header.rs
@@ -208,10 +208,13 @@ impl EarlyProps {
                 config.parse_name_value_directive(line, "needs-llvm-components")
             {
                 let components: HashSet<_> = config.llvm_components.split_whitespace().collect();
-                if !needed_components
+                if let Some(missing_component) = needed_components
                     .split_whitespace()
-                    .all(|needed_component| components.contains(needed_component))
+                    .find(|needed_component| !components.contains(needed_component))
                 {
+                    if env::var_os("COMPILETEST_NEEDS_ALL_LLVM_COMPONENTS").is_some() {
+                        panic!("missing LLVM component: {}", missing_component);
+                    }
                     return true;
                 }
             }