Factor out platforms for which libc is empty

Author: gnzlbg

.travis.yml

@@ -90,6 +90,10 @@ matrix:
     # QEMU based targets that compile in an emulator
     - env: TARGET=x86_64-unknown-freebsd
 
+    - env: TARGET=wasm32-unknown-unknown
+      install: rustup target add $TARGET
+      script: cargo build --no-default-features --target $TARGET --release
+
 notifications:
   email:
     on_success: never

README.md

@@ -1,8 +1,7 @@
 libc
 ====
 
-A Rust library with native bindings to the types and functions commonly found on
-various systems, including libc.
+Rust wrapper over the system's `libc`.
 
 [![Build Status](https://travis-ci.org/rust-lang/libc.svg?branch=master)](https://travis-ci.org/rust-lang/libc)
 [![Build status](https://ci.appveyor.com/api/projects/status/github/rust-lang/libc?svg=true)](https://ci.appveyor.com/project/rust-lang-libs/libc)