Description of _Bool in registers (outside of arg-passing / returning) is overly specific.

[Peter Cordes]

Section 2.1.1 includes this language: 

Booleans, when stored in a memory object, are stored as single byte objects the value of which is always 0 (false) or 1 (true). When stored in integer registers (except for passing as arguments), all 4 bytes of the register are significant; any nonzero value is considered true.

This only says "except for passing", implying that it applies to returning, but that's not the case.  The ABI should just drop that wording that tries to specify what functions should do internally. 

https://github.com/hjl-tools/x86-psABI/issues/5