whitelist x86 fxsr feature

src/librustc_trans/llvm_util.rs

@@ -85,7 +85,8 @@ unsafe fn configure_llvm(sess: &Session) {
                                                  "avx512dq\0", "avx512er\0",
                                                  "avx512f\0", "avx512ifma\0",
                                                  "avx512pf\0", "avx512vbmi\0",
-                                                 "avx512vl\0", "avx512vpopcntdq\0", "mmx\0"];
+                                                 "avx512vl\0", "avx512vpopcntdq\0",
+                                                 "mmx\0", "fxsr\0"];
 
 const HEXAGON_WHITELIST: &'static [&'static str] = &["hvx\0", "hvx-double\0"];