Previously foreign statics would actually cause a local static to be
defined and exported. This issue was found because std::env::vars() was
found to return no env vars despite many being defined. This was caused
by libstd importing environ as foreign static. The accidental definition
of environ caused libstd to read a null pointer which was interpreted as
there being no environment variables at all.
Also fix tests. STDOUT is not defined by libc. The correct name is stdout.
This previously worked as STDOUT was incorrectly defined as null pointer
during codegen.
