Install PNaCl SDK
Configure to be built using PNaCl's Clang toolchain
https://developer.chrome.com/native-client/devguide/devcycle/building
Use gnu++11 as standard library, because newlib
relies on GNU extensions.
./configure --with-charset=utf8 CXXFLAGS="-std=gnu++11 -O2" CFLAGS="-O2" CXX="pnacl-clang++"