Rollup merge of rust-lang#126399 - onur-ozkan:126156, r=albertlarsan68

extend the check for LLVM build

We don't build LLVM when using the precompiled version from the CI builder.

Closes rust-lang#126156

Author: matthiaskrgr

src/bootstrap/src/core/sanity.rs

@@ -137,19 +137,20 @@ pub fn check(build: &mut Build) {
     }
 
     // We need cmake, but only if we're actually building LLVM or sanitizers.
-    let building_llvm = build
-        .hosts
-        .iter()
-        .map(|host| {
-            build.config.llvm_enabled(*host)
-                && build
-                    .config
-                    .target_config
-                    .get(host)
-                    .map(|config| config.llvm_config.is_none())
-                    .unwrap_or(true)
-        })
-        .any(|build_llvm_ourselves| build_llvm_ourselves);
+    let building_llvm = !build.config.llvm_from_ci
+        && build
+            .hosts
+            .iter()
+            .map(|host| {
+                build.config.llvm_enabled(*host)
+                    && build
+                        .config
+                        .target_config
+                        .get(host)
+                        .map(|config| config.llvm_config.is_none())
+                        .unwrap_or(true)
+            })
+            .any(|build_llvm_ourselves| build_llvm_ourselves);
 
     let need_cmake = building_llvm || build.config.any_sanitizers_to_build();
     if need_cmake && cmd_finder.maybe_have("cmake").is_none() {