rustc_llvm: Link to libkstat on Solaris/SPARC

getHostCPUName calls into libkstat but as of
LLVM 16.0.6 libLLVMTargetParser is not explicitly
linked against libkstat causing builds to fail
due to undefined symbols.

See also: llvm/llvm-project#64186

Author: Alex Zepeda

compiler/rustc_llvm/build.rs

@@ -241,6 +241,11 @@ fn main() {
         cmd.arg("--system-libs");
     }
 
+    // We need libkstat for getHostCPUName on SPARC builds.
+    if target.starts_with("sparcv9") && target.contains("solaris") {
+        println!("cargo:rustc-link-lib=kstat");
+    }
+
     if (target.starts_with("arm") && !target.contains("freebsd"))
         || target.starts_with("mips-")
         || target.starts_with("mipsel-")