no -Bsymbolic for mac; no static-libstdc++ for windows

Author: japaric

src/bootstrap/native.rs

@@ -176,7 +176,13 @@ impl Step for Llvm {
 
         // For distribution we want the LLVM tools to be *statically* linked to libstdc++
         if builder.config.llvm_tools_enabled {
-            cfg.define("CMAKE_EXE_LINKER_FLAGS", "-Wl,-Bsymbolic -static-libstdc++");
+            if !target.contains("windows") {
+                if target.contains("apple") {
+                    cfg.define("CMAKE_EXE_LINKER_FLAGS", "-static-libstdc++");
+                } else {
+                    cfg.define("CMAKE_EXE_LINKER_FLAGS", "-Wl,-Bsymbolic -static-libstdc++");
+                }
+            }
         }
 
         if target.contains("msvc") {