Unrolled build for #150010

Rollup merge of #150010 - androm3da:bcain/make_test_linkage, r=jieyouxu

Correct library linking for hexagon targets in run-make tests

Fixes the run-make test framework to use target-specific library linking instead of host-based detection. Previously, tests for hexagon targets failed because the framework used uname() to detect libraries to link, which returned Linux libraries (-lm -lrt -ldl -lpthread) that don't exist on all hexagon targets.

- Use target() instead of uname() to detect cross-compilation targets
- Add hexagon-specific library configuration (-lunwind -lclang_rt.builtins-hexagon)
- Maintain backward compatibility for host-native compilation

This enables hexagon tests to compile and link successfully with the appropriate runtime libraries for the hexagon platform.

Author: rust-timer

src/tools/run-make-support/src/external_deps/c_cxx_compiler/extras.rs

@@ -1,4 +1,4 @@
-use crate::{is_arm64ec, is_win7, is_windows, is_windows_msvc, uname};
+use crate::{is_arm64ec, is_win7, is_windows, is_windows_msvc, target, uname};
 
 fn get_windows_msvc_libs() -> Vec<&'static str> {
     let mut libs =
@@ -22,14 +22,22 @@ pub fn extra_c_flags() -> Vec<&'static str> {
             vec!["-lws2_32", "-luserenv", "-lbcrypt", "-lntdll", "-lsynchronization"]
         }
     } else {
-        match uname() {
-            n if n.contains("Darwin") => vec!["-lresolv"],
-            n if n.contains("FreeBSD") => vec!["-lm", "-lpthread", "-lgcc_s"],
-            n if n.contains("SunOS") => {
-                vec!["-lm", "-lpthread", "-lposix4", "-lsocket", "-lresolv"]
+        // For cross-compilation targets, we need to check the target, not the host
+        let target_triple = target();
+        if target_triple.contains("hexagon") {
+            // Hexagon targets need unwind support but don't have some Linux libraries
+            vec!["-lunwind", "-lclang_rt.builtins-hexagon"]
+        } else {
+            // For host-based detection, fall back to uname() for non-cross compilation
+            match uname() {
+                n if n.contains("Darwin") => vec!["-lresolv"],
+                n if n.contains("FreeBSD") => vec!["-lm", "-lpthread", "-lgcc_s"],
+                n if n.contains("SunOS") => {
+                    vec!["-lm", "-lpthread", "-lposix4", "-lsocket", "-lresolv"]
+                }
+                n if n.contains("OpenBSD") => vec!["-lm", "-lpthread", "-lc++abi"],
+                _ => vec!["-lm", "-lrt", "-ldl", "-lpthread"],
             }
-            n if n.contains("OpenBSD") => vec!["-lm", "-lpthread", "-lc++abi"],
-            _ => vec!["-lm", "-lrt", "-ldl", "-lpthread"],
         }
     }
 }