"constexpr constructor" and "constexpr function" are defined terms and should not be formatted in code font

[zygoloid]

Some of the references to the defined terms "constexpr constructor" and "constexpr function" incorrectly use code font for the "constexpr" keyword. (We probably make this mistake for some other terms that include keywords, too.)

[jwakely]

I wondered about this while applying the recent motions and followed the lead of [expr.const] which uses code font consistently. Getting it right there would set a good example :)

[jlaire]

This seems to be a duplicate of #559 (which is tagged "decision-required).

[tkoeppe]

@jensmaurer: Could you please have a look at both issues?

[jensmaurer]

I've closed #559 as a duplicate.