__aligned__ attribute doesn't parse correctly

struct a{int b;} b __attribute__((__aligned__));

gcc says it's okay, clang gives an error. (From pthread.h.)


This is definitely ok. We should accept and ignore it for now (as well as the version that takes an argument).

This will let you compile code that uses pthread.h but will break codegen for that particular struct. In time we should add packed codegen support as well,