Auto merge of #136 - asajeffrey:pass-cxx-flags-to-bindgen, r=jdm

Pass CXXFLAGS to bindgen

Bindgen doesn't pass CXXFLAGS to clang, which causes cross-compile issues, e.g. http://build.servo.org/builders/android/builds/11618.

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Author: bors-servo

build.rs

@@ -159,6 +159,12 @@ fn build_jsapi_bindings() {
         builder = builder.clang_arg("-fms-compatibility");
     }
 
+    if let Ok(flags) = env::var("CXXFLAGS") {
+        for flag in flags.split_whitespace() {
+            builder = builder.clang_arg(flag);
+        }
+    }
+
     for flag in cc_flags() {
         builder = builder.clang_arg(flag);
     }