Auto merge of #200 - jdm:uwp-rustc-with-cpp-changes, r=asajeffrey

Add cargo feature to build with UWP support.

These changes remove a bunch of forbidden API uses. I've tested a local build and it starts up and can successfully JIT some rAF code in a WebGL example.

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Author: bors-servo

Cargo.toml

@@ -18,6 +18,7 @@ exclude = [
 [features]
 debugmozjs = []
 profilemozjs = []
+uwp = []
 
 [lib]
 name = "mozjs_sys"

build.rs

@@ -120,6 +120,9 @@ fn build_jsapi() {
         if target.contains("gnu") {
             println!("cargo:rustc-link-lib=stdc++");
         }
+        if cfg!(feature = "uwp") {
+            println!("cargo:rustc-link-lib=mincore");
+        }
     } else if target.contains("apple") || target.contains("freebsd") {
         println!("cargo:rustc-link-lib=c++");
     } else {